An objective tool to measure the effect of botulinum toxin in blepharospasm and hemifacial spasm.

BACKGROUND AND PURPOSE: It is challenging to assess patients with blepharospasm (BSP) and hemifacial spasm (HFS) as these patients exhibit a wide range of amplitudes of eyelid movements. In order to quantify these movements, a mathematical algorithm, i.e. Fast Fourier Transform, can be employed to convert the signal from the time domain to the frequency domain. The result of this quantification represents the energy generated during the eyelid movements. In order to objectively assess the therapeutic effects of botulinum toxin (BoNT) in these patients, we evaluated the energy generated by the upper eyelid during spontaneous eyelid movements before and after treatment. METHODS: A total of 39 patients with BSP and HFS were evaluated before and 30 days after receiving onabotulinum toxin A injections. A high-speed camera and micro light-emitting diodes were used to register the spontaneous eyelid movements. The result of the quantification obtained using Fast Fourier Transform permitted assessment of the activity associated with the eyelid movements. RESULTS: We studied 78 eyelids. The total energy generated during spontaneous eyelid movements was significantly reduced after treatment in the patients with BSP (P = 0.0018) and on the affected side in the patients with HFS (P = 0.0058). CONCLUSIONS: The assessment of the energy generated by the upper eyelid during spontaneous eyelid movements enabled us to measure the therapeutic effects of BoNT in patients with these conditions. The use of this system could enable customized and fine adjustments to BoNT doses based on each patient's needs.

Reliability of ultrasonographic measurements of bovine sole structures in relation to sole horn thickness, measured by computed tomography, and sole horn hardness.

The goal of the present study was to determine the effect of sole horn thickness (SHT) and sole horn hardness (SHD) on ultrasonographic visualization of sole structures in the inner and outer claws of 150 Holstein-Friesian cows, and to evaluate different ultrasound frequencies for this purpose. Ultrasonographic views of the sole structure were considered complete when 3 echogenic lines, representing the ventral surface of the sole horn, the borders of the sole horn and soft-tissue layer, and the ventral surface of the distal phalanx, were seen. The proportion of complete ultrasonographic views of the sole structures, designated as the ultrasonographic visualization proportion (UVP), and the measurement errors of SHT were evaluated by comparing images from computed tomography (CT) and ultrasonography. The latter images were generated using 3 different probes, frequencies of 6.5 and 5.0 MHz, and 2 different ultrasound machines (#1 and #2) to assess the apex, middle, and heel regions of the claws. The UVP were 60.8 to 77.9% for the 6.5-MHz probe in ultrasound machine #1 (probe A), which were lower than those (>90%) for both the 5.0-MHz probe in ultrasound machine #1 (probe B) and the 5.0-MHz probe in ultrasound machine #2 (probe C). The UVP was significantly lower in claws with an SHD ≥50 units than in claws with an SHD <40 or 40 to <50 units (UVP: 77.1% compared with 93.7 and 91.4%, respectively) when measured with probe B. In claws with an SHT <10 mm, the UVP was significantly lower when SHD was ≥50 units compared with <40 or 40 to >50 units; the values were 69.0% versus 91.3 and 85.9%, respectively, for probe A, and 89.7% versus 100 and 100%, respectively, for probe B. When SHT were measured by either probes A or B in ultrasound machine #1, the proportions of claws in which ultrasonographic values were within a ±1 mm range compared with the values obtained by CT were 84.9 to 91.3% for CT-determined SHT <5 mm, 66.7 to 71.9% for CT-determined SHT 5 to <7 mm, 28.9 to 51.2% for CT-determined SHT 7 to <10 mm, and 6.2 to 19.7% for CT-determined SHT ≥10 mm. The data indicated that increased SHT was associated with a decrease in ultrasonographic measurement accuracy. In claws with an SHT <5 mm, the high proportion of ultrasonographic values that were accurate within a ±1 mm range suggests that this imaging modality would be useful in cows with thin soles.

Clinical features of 32 new Japanese cases with autoimmune haemorrha-philia due to anti-factor XIII antibodies.

INTRODUCTION: Autoimmune haemophilia-like disease (or haemorrha-philia) due to anti-factor XIII (FXIII; F13 to avoid confusion with FVIII or FXII) antibodies (termed AH13) is a severe bleeding disorder. Although AH13 is thought to be rare, 'the number of its diagnosed patients' has recently increased in Japan. However, its prevalence remains unknown. AIM: To improve understanding of this disease, we examined and diagnosed 32 'new' Japanese patients with AH13. METHODS: The presence of antibodies against F13-A subunit and/or F13-B subunit was confirmed by using a dot blot test and enzyme-linked immunosorbent assays. RESULTS: Most of our patients had autoantibodies against the F13-A subunit (88%). A predominance of men (59%) was observed. The mean age and residual F13 activity of our AH13 cohort were 71.7 years and 10.5% of normal, respectively, and 53% of cases were idiopathic. Autoimmune disorders and malignancies were the leading underlying disease (both 16%). Intramuscular and subcutaneous bleeding were the leading symptoms (both 72%). Most of our patients were treated with F13 concentrates (72%) to arrest bleeding and with prednisolone (81%) to eradicate anti-F13 autoantibodies. Cyclophosphamide and rituximab (both 25%) were also administered. The mortality of AH13 was high (22%), and haemorrhage was the major cause of death (71%). Moreover, 13% of our AH13 patients were diagnosed after haemorrhagic death. CONCLUSION: Physicians/haematologists must raise the awareness of AH13 as a life-threatening disease. This report represents the only experience of a nationwide survey, and may contribute to a diagnosis on potentially overlooked non-Japanese AH13 patients in other countries in the world.

Quantitative evaluation of the relationship between dorsal wall length, sole thickness, and rotation of the distal phalanx in the bovine claw using computed tomography.

Computed tomography (CT) was performed on 800 untrimmed claws (400 inner claws and 400 outer claws) of 200 pairs of bovine hindlimbs to investigate the relationships between dorsal wall length and sole thickness, and between dorsal wall length and the relative rotation angle of distal phalanx-to-sole surface (S-D angle). Sole thickness was 3.8 and 4.0 mm at the apex of the inner claws and outer claws, respectively, with dorsal wall lengths <70 mm. These sole thickness values were less than the critical limit of 5 mm, which is associated with a softer surface following thinning of the soles. A sole thickness of 5 mm at the apex was estimated to correlate with dorsal wall lengths of 72.1 and 72.7 mm for the inner and outer claws, respectively. Sole thickness was 6.1 and 6.4 mm at the apex of the inner and outer claws, respectively, with dorsal wall lengths of 75 mm. These sole thickness values were less than the recommended sole thickness of 7 mm based on the protective function of the soles. A sole thickness >7 mm at the apex was estimated to correlate with a dorsal wall length of 79.8 and 78.4mm for the inner and outer claws, respectively. The S-D angles were recorded as anteversions of 2.9° and 4.7° for the inner and outer claws, respectively, with a dorsal wall length of 75 mm. These values indicate that the distal phalanx is likely to have rotated naturally forward toward the sole surface. The distal phalanx rotated backward to the sole surface at 3.2° and 7.6° for inner claws with dorsal wall lengths of 90-99 and ≥100 mm, respectively; and at 3.5° for outer claws with a dorsal wall length ≥100 mm. Dorsal wall lengths of 85.7 and 97.2 mm were estimated to correlate with a parallel positional relationship of the distal phalanx to the sole surface in the inner and outer claws, respectively.

Utility of 5-aminolaevulinic acid fluorescence-guided endoscopic biopsy for malignant mesothelioma in a cat and dog.

Malignant mesothelioma (MM) is uncommon in cats and dogs and can be challenging to diagnose. Adequate tissue sampling is required for superior diagnostic accuracy. Protoporphyrin IX, a metabolite of 5-aminolaevulinic acid (5-ALA), is a photosensitiser for photodynamic diagnosis (PDD). To the best of our knowledge, no study has reported the use of 5-ALA-PDD to detect MM in veterinary medicine. The present study describes the use of 5-ALA-PDD for MM diagnosis in a cat and dog, as well as the effectiveness of intracavitary chemotherapy. We evaluated the use of PDD with 5-ALA hydrochloride (5-ALA-PDD) in two cases of MM. A 12-year-old cat presented with a 1-month history of respiratory distress, and a 9-year-old dog presented with a 3-month history of mild abdominal distention. We endoscopically biopsied lesions in both the cases using 5-ALA-PDD. Histopathological examination revealed mesothelioma, and immunohistochemical staining was positive for calretinin. Both patients were treated with carboplatin. The cat died of respiratory failure. Although, the dog's condition improved 21 days after the first chemotherapeutic drug administration, the dog died on day 684 owing to cardiac-related issues. 5-ALA-PDD is thus, safe and feasible for the diagnosis of MM in veterinary medicine.

Quantitative evaluation of bone development of the distal phalanx of the cow hind limb using computed tomography.

Computed tomography (CT) was performed on 400 claws (200 inner and 200 outer claws) of 100 pairs of bovine hind limbs to investigate the etiological theory that an exacerbating factor for ulceration is exostosis of the tuberculum flexorium within the distal phalanx. A variety of morphological changes of the tuberculum flexorium of bovine hind limb claws was visualized by 3-dimensional CT, and the geometry of these claws suggested a growth pattern of bone development with respect to the assumed daily loading patterns. This growth occurs initially at the abaxial caudal aspect of the distal phalanx and is followed by horizontal progression toward the axial aspect. The length of downward bone development on the solar face of the distal phalanx was 2.73±1.32 mm in the outer claws, significantly greater than in the inner claws (2.38±0.96 mm). Ratios of downward (vertical) bone development to the thickness of the subcutis and the corium (VerBD ratios) did not differ between the outer and inner claws (36.7 vs. 38.3%, respectively). Ratios of horizontal bone development to the axial-to-abaxial line of the tuberculum flexorium (HorBD ratios) were approximately 60% for both outer and inner claws. These quantitative measures regarding horizontal and vertical bone development within the distal phalanx were positively correlated with age and VerBD ratios (r=0.53 and r=0.36 for the inner and outer claws, respectively). Correlations between claw width of the outer claw and length of vertical bone development (r=0.43), the HorBD ratio (r=0.51), and the VerBD ratio (r=0.42) suggested that the relative size difference between the inner and outer claws enhances bone development in the outer claw. Correlation coefficients between VerBD and HorBD ratios (r=0.52 and 0.63 for the inner and outer claws, respectively) suggested that horizontal and vertical bone development occurs as a synchronized process within the tuberculum flexorium. This age-related progress of bone development within the tuberculum flexorium is associated with increased exposure to several exacerbating factors and the laminitic process.

Contrast-enhanced ultrasonography for characterization of focal splenic lesions in dogs.

BACKGROUND: Contrast-enhanced ultrasonography with perflubutane microbubbles improves the diagnostic accuracy to differentiate benign and malignant focal liver lesions in dogs. HYPOTHESIS: Perflubutane microbubbles-enhanced ultrasonography is useful for differentiation of benign from malignant focal splenic lesions in dogs. ANIMALS: Twenty-nine clinical dogs with single or multiple focal splenic lesions detected by conventional ultrasonography. METHODS: Prospective clinical observational study. Perflubutane microbubbles-enhanced ultrasonography was performed in 29 dogs with focal splenic lesions. Qualitative assessment of the enhancement pattern was performed in the early vascular, late vascular, and parenchymal phases. RESULTS: In the early vascular phase, a hypoechoic pattern was significantly associated with malignancy (P=.02) with sensitivity of 38% (95% confidence interval [CI], 25-38%) and specificity of 100% (95% CI, 84-100%). In the late vascular phase, a hypoechoic pattern was significantly associated with malignancy (P=.001) with sensitivity of 81% (95% CI, 66-90%) and specificity of 85% (95% CI, 65-95%). There was no significant difference between malignant and benign lesions during the parenchymal phase. CONCLUSIONS AND CLINICAL IMPORTANCE: Hypoechoic splenic nodules in the early and late vascular phases with perflubutane microbubbles-enhanced ultrasonography are strongly suggestive of malignancy in dogs.

Photodynamic detection of a canine glioblastoma using 5-aminolevulinic acid.

Photodynamic detection using 5-aminolevulinic acid has been used to identify the surgical margins during resection of human primary brain tumours. Although there are some reports on its use in malignant tumours in veterinary medicine, it has never been used for primary brain tumours. Here we describe a canine glioblastoma that was detected at autopsy with protoporphyrin IX fluorescence induced by orally administered 5-aminolevulinic acid. The fluorescence was strongest towards the centre of the lesion and was absent in normal brain tissue. Moreover, the fluorescence findings were consistent with MRI and histopathological findings. Our findings suggest that photodynamic detection using 5-aminolevulinic acid might be useful for intraoperative fluorescence-guided resection of malignant gliomas in dogs.

Prevalence of Helicobacter and Acanthamoeba in natural environment.

AIMS: We examined whether the presence of Helicobacter is related to that of Acanthamoeba in river and soil environments. METHODS AND RESULTS: The samples (river n = 51, soil n = 75) were collected in Sapporo City, Japan. PCR with primers for Helicobacter genus-specific and standard culture techniques were used to detect helicobacter. Prevalence of acanthamoeba was also evaluated by genus-specific PCR. The prevalence of Helicobacter genus-specific DNA in river water samples and in soil samples was 88% and 0%, respectively. No successful culture of helicobacter was achieved. The prevalence of Acanthamoeba genus-specific DNA in river samples and in soil samples was 61% and 96%, respectively. No statistical correlation between the prevalence of helicobacter and either that of acanthamoeba or water quality parameters (pH, turbidity and coliform group) except for temperature was found. CONCLUSIONS: We revealed the presence of helicobacter in river water and non-existence of helicobacter in soil. However, the distribution of helicobacter did not overlap with that of acanthamoeba in rivers. SIGNIFICANCE FOR IMPACT OF THE STUDY: The role of acanthamoeba on the survival of helicobacter might be limited as the both are coincidentally present in the environment.

Inverse correlation between NKG2D expression on CD8+ T cells and the frequency of CD4+CD25+ regulatory T cells in patients with esophageal cancer.

Although malignant diseases are known to be associated with immune suppression, detailed mechanisms of this phenomenon are still unknown. NKG2D is an activating cell surface receptor expressed by natural killer (NK) cells and CD8+ T cells, and it has been reported that NKG2D engagement is extremely important for T cell activation. In the current study, NKG2D expression on CD8+ T cells and the frequency of CD4+ CD25+ regulatory T (Treg) cells were determined by multicolor flow cytometry to investigate one of the mechanisms responsible for immune evasion in esophageal cancer patients. NKG2D expression on CD8+ T lymphocytes in esophageal cancer patients was significantly lower than in those of normal controls. NKG2D expression in T3/T4 esophageal cancer was significantly lower than that in T1/T2 esophageal cancer. CD8+ T cells from patients with lymph node metastasis expressed significantly lower NKG2D than those without lymph node metastasis. Moreover, significantly lower NKG2D expression was observed in stage III/IV cancer in comparison with stage I/II. The frequency of CD4+CD25+ Treg cells in esophageal cancer patients was significantly higher than those in normal controls. NKG2D expression on CD8+ T cells was significantly inversely correlated with the frequency of CD4+CD25+ Treg cells in esophageal cancer patients. Our data indicates that decreased NKG2D expression on CD8+ T cells is correlated with disease severity. Decreased NKG2D expression and an increase in Treg cells may be one of the key mechanisms responsible for immune evasion in esophageal cancer.

Thymidine kinase-1/CD31 double immunostaining for identifying activated tumor vessels.

Although angiogenesis plays a crucial role in cancer growth and progression, no reliable method for assessing angiogenesis in tumor tissue sections currently is available. Using biomarkers with high specificity for proliferating endothelial cells could help quantify angiogenic activity. Thymidine kinase-1 (TK1) is an enzyme involved in the salvage pathway of DNA synthesis and its activity is correlated with cell proliferation. We investigated the use of double immunostaining for TK1 and CD31 for identifying activated tumor vessels. Differences in TK1/CD31 positive vessel rates (PVRs) between tumor and adjacent normal tissues were evaluated in 39 colorectal carcinoma (CRC) samples and compared with those of Ki67/CD31 double stained tissues. Mean TK1/CD31 PVR (23.6%) in CRCs was 13.9 fold greater than in adjacent normal tissues (1.7%)). By comparison, mean Ki67/CD31 PVR in CRCs was 20.0%, i.e. only 4.8 fold greater than in normal tissues (4.2%). Also, mean TK1/CD31 PVR in normal tissues was significantly less than mean Ki67/CD31 PVR. Our findings indicate that double immunostaining for TK1/CD31 can detect activated tumor vessels more accurately than staining for Ki67/CD31 and potentially could identify tumors that will respond to anti-angiogenic therapy.

CT colonography to detect rectosigmoid involvement in patients with primary ovarian cancer.

INTRODUCTION: We retrospectively evaluated the performance of preoperative computed tomographic (CT) colonography to detect tumor involvement of the rectosigmoid wall and predict the need for rectosigmoid resection in patients with primary ovarian cancer. METHODS: Thirty-three patients with primary ovarian cancer who underwent preoperative CT colonographic examination were evaluated. The images of the examination were analyzed and compared with the subsequent surgical findings. RESULTS: All abnormal findings (malignant infiltration of the rectosigmoid mucosa and extrinsic compression) revealed by conventional colonoscopy were correctly observed as extrinsic compression using CT colonography. The sensitivity, specificity, positive predictive value and negative predictive value of CT colonography for the prediction of rectosigmoid resection were 100%, 64.7%, 72.7%, and 100%, respectively. Though conventional colonoscopic examinations could not be completed in five patients because of the presence of extrinsic stenosis and occlusion at the sigmoid colon, CT colonography enabled the entire large bowel to be examined in these patients. CONCLUSIONS: This preliminary study showed that the CT colonographic examination is feasible and safe. CT colonography seems to have several advantages over conventional colonoscopy for the detection of rectosigmoid involvement in patients with advanced ovarian cancer. For confirmation of the efficacy of CT colonography, further large prospective studies are needed.

Photodynamic detection of canine mammary gland tumours after oral administration of 5-aminolevulinic acid.

5-Aminolevulinic acid (5-ALA) is widely used in photodynamic detection (PDD) and therapy. We evaluated the pharmacokinetics of 5-ALA-induced porphyrins and its effectiveness in PDD in dogs with mammary gland tumours (MGTs) following oral administration. Healthy dogs and those with MGTs (nine each) were orally administered 4 mg kg-1 5-ALA. Protoporphyrin IX (PpIX) was not detected in the plasma of healthy dogs but it peaked in dogs with MGT at 2 h after 5-ALA administration. In the PDD study, 16 dogs with MGT were orally administered 40 mg kg-1 5-ALA, and MGT but not normal tissue showed red fluorescence after 2-4 h. Photon counts were 6635-63 890 and 59-4011 (median, 19 943 and 919) for MGT and non-tumour tissues, respectively. Cell density strongly correlated with PpIX photon counts of MGT tissue of the dogs (R = 0.743, P = 0.0009). We suggest that 5-ALA-PDD might be an effective diagnostic tool for MGTs.

Mutations of the p53 gene as a predictor of poor prognosis in patients with non-small-cell lung cancer.

BACKGROUND: Inactivation of the p53 tumor suppressor gene (also known as TP53) through a point mutation and/or loss of heterozygosity is one of the most common genetic changes found in various types of human tumors. PURPOSE: Our purpose was to investigate the relationship between the presence of p53 gene mutations and survival of patients with non-small-cell lung cancer (NSCLC) of all stages who underwent surgery with preoperative curative intent as a routine therapeutic intervention. The prognostic significance of factors like sex, age, tumor histology, and the stage of the disease was also evaluated. METHODS: We analyzed 120 tumor specimens from patients with histologically confirmed NSCLC for p53 mutations occurring in exons 5 through 8 by polymerase chain reaction-single-strand conformation polymorphism assay of genomic DNA. Univariate and multivariate analyses were performed to assess the association between p53 mutations and the survival of the NSCLC patients. RESULTS: Fifty-one (43%) of 120 tumor specimens showed p53 mutations. Overall, the p53 mutations did not correlate with sex, age, or the clinical stage of the disease but showed frequent association with tumors of squamous cell histology. Univariate analysis revealed that the patients with p53 mutations survived for a significantly shorter period of time after surgery than those without the mutations (P = .0100, logrank test). The presence of p53 mutations was a significant prognostic factor in the patients with advanced disease (stages IIIA through IV) (P = .0091) but not in those with early disease (stages I and II) (P = .2837). Multivariate analysis using the Cox proportional hazards model found independent prognostic significance for p53 mutations (hazards ratio [HR] = 1.84; P = .018) and advanced disease stage (HR = 2.20; P = .003). The model also predicted the lower risk for female patients (HR = 0.51; P = .040). CONCLUSION: The occurrence of p53 mutations in some NSCLC tumors may be independently associated with a shortened overall survival and may be of somewhat more prognostic significance in patients with advanced stage than in those with early stage of the disease. IMPLICATION: Detection of p53 mutations may help in the selection of NSCLC patients suitable for appropriate investigational therapeutic strategies in view of improving their survival and quality of life.

Gene therapy for carcinoembryonic antigen-producing human lung cancer cells by cell type-specific expression of herpes simplex virus thymidine kinase gene.

A carcinoembryonic antigen (CEA)-producing human lung cancer cell line (A549), a nonproducing human lung cancer cell line (CADO-LC9), and a human uterine cervical cancer (HeLa) were transfected with the herpes simplex virus thymidine kinase (HSV-TK) gene regulated by 445 nucleotides upstream from the translational start of CEA gene. Fifty % growth inhibitory concentration of ganciclovir (GCV) was 0.57 micron for HSV-TK-transfected A549; relative sensitivity to GCV was more than 1000 times higher compared to the 50% growth inhibitory concentration of the parental cell line. Both CADO-LC9 and HeLa transfected with HSV-TK were still resistant to GCV. There was no difference in either morphology or doubling time between HSV-TK-transfected and parental clones. Injections (i.p.) of GCV resulted in significant regression of HSV-TK-transfected A549 tumors in nude mice. These data show the possibility of gene therapy using the cell type-specific promoter of CEA gene against CEA-producing adenocarcinoma of the lung.

Eradication of Myc-overexpressing small cell lung cancer cells transfected with herpes simplex virus thymidine kinase gene containing Myc-Max response elements.

Herpes simplex virus thymidine kinase (HSV-TK) gene was ligated with four repeats of the Myc-Max response elements (a core nucleotide sequence CACGTG), and its utility for gene therapy was examined by the treatment of either c-, L- or N-myc-overexpressing the small cell lung cancer (SCLC) cell line with ganciclovir (GCV). The chloramphenicol acetyltransferase assay demonstrated that the overexpression of any myc genes activated transcription from the CAT gene depending on the Myc-Max binding sites. The transduction of the HSV-TK gene ligated with the CACGTG core rendered all three SCLC lines to be more sensitive to GCV than parental ones in vitro. In addition, the growth of c- or L-myc-overexpressing SCLC cells containing the hybrid HSV-TK gene were significantly suppressed by GCV in vivo. When parental SCLC cells were mixed with HSV-TK-expressing tumor cells at a ratio of 1:3, GCV treatment inhibited tumor growth by 90% compared with parental cells only, indicating the existence of the "bystander effect." These data suggest that the CACGTG-driven HSV-TK gene may be useful for the treatment of SCLC overexpressing any type of myc family oncogenes.

Generation of a small cell lung cancer variant resistant to lymphokine-activated killer (LAK) cells: association with resistance to a LAK cell-derived, cytostatic factor.

Cells of OS2-RA, a human small cell lung cancer line sensitive to lymphokine-activated killer (LAK) cells, were repeatedly cocultured with human LAK cells. Fourteen cycles of the coculture produced a variant, termed OS2-RA-R, capable of growing successfully in the presence of LAK cells. OS2-RA-R showed a moderate resistance to lysis by LAK cells in 4-h 51Cr release assays. OS2-RA-R acted positively as a cold target for lysis of OS2-RA by LAK cells, suggesting no loss of the binding site for LAK cells on the cell surface of the variant. On the other hand, LAK cells were shown to produce a factor capable of suppressing the proliferation of OS2-RA and certain other cell lines but not lymphocytes. Interestingly, OS2-RA-R exhibited a substantial resistance to the cytostatic activity of LAK cell supernatants. The cytostatic factor, eluted at the 57-kDa fraction in gel filtration, showed no activity of interleukin 1, gamma-interferon, transforming growth factor beta, or tumor necrosis factor. These results suggest that LAK cells exhibit antitumor activity through not only rapid cytolysis but also slow-acting cytokine production, and the successful growth of OS2-RA-R in a coculture with LAK cells is the result of acquiring resistance to these two different LAK cell phenomena.

A frequent deletion of chromosome 5q21 in advanced small cell and non-small cell carcinoma of the lung.

We have examined the deletion of the long arm of chromosome 5 (5q) in 59 cases of advanced lung cancer [39 cases of small cell lung cancer (SCLC), 20 cases of non-SCLC] using 12 restriction fragment length polymorphism markers on 5q. Of 59 lung cancer cases, 48 (81%) exhibited deletion at any portion of the 5q locus (loci). Such a high frequency of 5q deletion has not been reported in surgically resectable non-SCLC. One SCLC case showed a 5q deletion only in metastatic sites but not in the primary cancer. These data suggest that the inactivation of putative tumor-suppressor gene(s) on 5q may be a late event in the progression of lung cancer. There was no significant difference in frequency of 5q deletion between SCLC and non-SCLC. Compared to non-SCLC, however, SCLC usually showed widespread deletion on 5q. While the most frequent target region was estimated to be about 3-5 megabases at 5q21 around the adenomatous polyposis coli (APC) gene locus, some cases showed more telomeric deletion (5q33-35), suggesting that there are at least two different tumor-suppressor genes on 5q associated with the progression of lung cancer.