CD68+ reactive histiocytosis complicating early gastric cancer

A peculiar form of reactive, non-granulomatous proliferation of CD68+ histiocytes was demonstrated, for the first time, in the submucosal layer just beneath the IIa-type early gastric adenocarcinoma that focally invaded submucosal lymphatics. The histiocytic cells possessed plump eosinophilic and often foamy cytoplasm and eccentric small nuclei with apparent nucleoli. They contained periodic acid-Schiff-reactive granules, and were further immunoreactive for lysozyme and alpha 1-antitrypsin. The infiltration was ill-defined, and partly involved the tunica muscularis mucosae and the proper muscle layer. Markers of epithelial cells, Langerhans' histiocytes, smooth muscle cells and myofibroblasts were all negative.

Molecular cloning of rat obese cDNA and augmented gene expression in genetically obese Zucker fatty (fa/fa) rats

The obese (ob) gene has recently been isolated through a positional cloning approach, the mutation of which causes a marked hereditary obesity and diabetes mellitus in mice. In the present study, we isolated rat ob cDNA and examined the tissue distribution of the ob gene expression in rats. We also studied the gene expression in genetically obese Zucker fatty (fa/fa) rats. The rat ob gene product, a 167 amino acid protein with a putative signal sequence, was 96 and 83% homologous to the mouse and human ob proteins, respectively. Northern blot analysis using the rat ob cDNA probe identified a single mRNA species of 4.5 kb in size in the adipose tissue, while no significant amount of ob mRNA was present in other tissues in rats. The ob gene was expressed in the adipose tissue with region specificities. The rank order of the ob mRNA level in the adipose tissue was epididymal, retroperitoneal, and pericardial white adipose tissue > mesenteric and subcutaneous white adipose tissue > or = interscapular brown adipose tissue. The ob gene expression occurred in mature adipocytes rather than in stromalvascular cells isolated from the rat adipose tissue. Expression of the ob gene was markedly augmented in all the adipose tissue examined in Zucker fatty (fa/fa) rats at the stage of established obesity. The present study leads to the better understanding of the physiologic and pathophysiologic roles of the ob gene.

Rapid transcriptional activation and early mRNA turnover of brain natriuretic peptide in cardiocyte hypertrophy. Evidence for brain natriuretic peptide as an "emergency" cardiac hormone against ventricular overload

We previously demonstrated that brain natriuretic peptide (BNP) is a cardiac hormone mainly produced in the ventricle, while the major production site of atrial natriuretic peptide (ANP) is the atrium. To assess the pathophysiological role of BNP in ventricular overload, we have examined the gene expression of BNP, In comparison with that of ANP, in a model of cardiac hypertrophy using cultured neonatal rat ventricular cardiocytes. During cardiocyte hypertrophy evoked by endothelin-1, Phenylephrine, or PMA, the steady state level of BNP mRNA increased as rapidly as the "immediate-early" induction of the c-fos gene expression, and reached a maximal level within 1 h. Actinomycin D, a transcriptional inhibitor, completely diminished the response, while the translational blocked with cycloheximide did not inhibit it. In contrast, ANP mRNA began to increase 3 h after the stimulation, and accumulated during cardiocyte hypertrophy. The BNP secretion from ventricular cardiocytes was also stimulated, more rapidly than the ANP secretion. Furthermore, the turnover of BNP mRNA was significantly faster than that of ANP mRNA, being consistent with the existence of AUUUA motif in the 3'-untranslated region of BNP mRNA. These results demonstrate that the gene expression of BNP is distinctly regulated from that of ANP at transcriptional and posttranscriptional levels, and indicate that the characteristics of the BNP gene expression are suitable for its possible role as an " emergency" cardiac hormone against ventricular overload.

Synthesis and mitogenic activity of nonreducing-sugar subunit analogs of bacterial lipid A composed only of 3-hydroxytetradecanoic acid and its homologs

Novel analogs of the nonreducing-sugar subunit of bacterial lipid A, which were composed only of 3-hydroxytetradecanoic acid and its homologs, were synthesized. These analogs exhibited significant mitogenic activity.

Tumour angiogenesis and tumour cell proliferation as prognostic indicators in gastric carcinoma

Tumour growth depends on neovascularisation and tumour cell proliferation. Factor VIII-related antigen (F-VIII RA) localises to vascular endothelium. Expression of proliferating cell nuclear antigen (PCNA) is correlated with cell proliferation. We investigated the correlation between the expression of these antigens and prognosis in gastric carcinoma. A total of 108 specimens resected from patients with gastric carcinoma were investigated by staining with monoclonal antibodies against F-VIII RA and PCNA. Microvessel count (MVC; the mean number of microvessels in the five areas of highest vascular density at 200 x magnification) and PCNA labelling index (PCNA LI; percentage of positive cells in more than 500 tumour cells) were determined. The results showed that prognosis was significantly worse in patients who had a tumour with a high MVC (16 or greater) or a high PCNA LI (42% or greater) than in those patients who had a tumour with a low MVC (less than 16) or a low PCNA LI (less than 42%). Furthermore, MVC was significantly associated with the risk of hepatic recurrence. In conclusion, both MVC and PCNA LI may be good prognostic indicators in patients with gastric carcinoma.

Inhibition by beraprost sodium of thrombin-induced increase in endothelial macromolecular permeability

Effect of beraprost sodium (BPS), a long-acting and orally active stable analogue of PGI2, on the macromolecular permeability of cultured vascular endothelial cells (HUVEC) was detected by the transport of FITC-albumin. Thrombin treatment resulted in induction of FITC-albumin transport across the endothelial cell monolayer. The albumin transport induced by thrombin was not accompanied by any damage to the cells. BPS had no effect on the permeability of resting endothelial monolayers, while BPS inhibited the thrombin-induced increase in the albumin permeability in a dose-dependent manner (30-1000 nM). Treatment of the cells with PGI2 or dibutyryl cAMP caused a significant inhibition of the thrombin-induced increase in the albumin permeability. These results strongly suggested that BPS suppressed the thrombin-induced macromolecular permeability in HUVEC through the elevation of its intracellular cAMP, and that BPS was a suppressor against inflammatory vascular changes such as exudation.

[Development of apoptosis induced by whole-body irradiation in murine liver]

Apoptosis is known to be induced by radiation. However, the correlation between radiation-induced apoptosis and radiation injury in tumors in vivo has been unclear. In this paper, we report the study of apoptosis induced by whole-body irradiation using an immunohistochemical technique to detect DNA fragmentation in murine liver. A dose of 7 Gy was employed as LD50/30. DNA fragmentation was observed 30 min after radiation, and it peaked between 1 and 6 hours. DNA fragmentation could be detected 48 hours after radiation in capillary endothelium. This study was able to reveal the development of radiation-induced apoptosis in the liver by detecting DNA fragmentation in situ.

A sensitive ELISA for the characterization of two forms of circulating intercellular adhesion molecule-1 in human plasma

Nine murine monoclonal antibodies (MAbs) raised against recombinant soluble intercellular adhesion molecule-1 (sICAM-1) were evaluated by means of ELISAs, and their neutralizing activity was investigated in two bioassays employing Raji cells activated with phorbol myristate acetate. Three of the MAbs inhibited autoaggregation of the activated cells and adhesion to sICAM-1 fixed on a plastic plate. Non-neutralizing antibody SM1-255 is directed to an epitope that was not recognized by the other eight MAbs. This property enabled us to develop two ELISAs employing SM1-255 as a liquid-phase antibody for the quantitation of sICAM-1 circulating (cICAM-1) in human plasma. One assay, employing non-neutralizing antibody WIS2-11 as a solid-phase, has a sensitivity of two pg/well with coefficients of variation of 3.6-5.8% (within assay) and 5.5-9.5% (between assay). The other assay, employing neutralizing antibody WIS5-85 as a solid-phase, has a sensitivity of four pg/well with coefficients of variation of 2.7-7.2% (within assay) and 9.2-11.2% (between assay). There was a discrepancy between cICAM-1 levels of human plasma determined by these two assays. All samples showed 2- to 5-times higher levels in the assay using WIS2-11 than in that using WIS5-85. The result from the gel electrophoresis employing Western blotting suggests that ICAM-1 circulates in at least two molecular forms with molecular masses of about 85 and 130 kDa and with different reactivities to WIS2-11 and WIS5-85.

A case of iatrogenic growth retardation induced by a corticosteroid-containing anti-allergic drug

A nine-year old boy developed reduced growth velocity at the age of seven. The peak plasma growth hormone (GH) response to 3,4-dihydroxyphenylalanine, GH-releasing factor and insulin was 10.2, 8.1 and 7.6 micrograms/l, respectively, suggesting that the GH reserve was slightly reduced. Serum cortisol was undetectable and urinary excretion of 17-hydroxycorticosteroid was low (0.22-0.31 mg/day), but there were no physical or biochemical signs of adrenocortical insufficiency. He had taken an anti-allergic drug containing 0.25 mg of betamethasone and 2 mg of d-chlorpheniramine maleate per tablet for about 2 years to treat allergic rhinitis. Catch-up growth occurred when this drug was stopped. The present case suggests that daily administration of 0.25 mg of betamethasone can induce growth retardation and that ingestion of corticosteroid-containing preparations needs to be excluded in children who develop short stature without other symptoms.

Left atrial function after Cox's maze operation concomitant with mitral valve operation

BACKGROUND

This study examined whether the atrial fibrillation that commonly occurs in patients with a mitral valve operation could be eliminated by a concomitant maze operation.

METHODS

Left atrial function after Cox's maze operation performed concomitantly with a mitral valve operation was evaluated in 10 patients ranging in age from 38 to 67 years (mean age, 54 years). Seven patients who had had coronary artery bypass grafting served as the control group. Using transthoracic echocardiography, the ratio between the peak speed of the early filling wave and that of the atrial contraction wave (A/E ratio) and the atrial filling fraction (AFF) were determined from transmitral flow measurements. These two indices have been considered to represent the contribution of left atrial active contraction to ventricular filling.

RESULTS

The A/E ratio and the AFF were significantly lower in the maze group (0.35 +/- 0.17 versus 0.97 +/- 0.28 [p < 0.01] and 17.6% +/- 8.8% versus 36.8% +/- 6.4% [p < 0.01], respectively). The A/E ratio and the AFF correlated inversely with age (r = -0.72, p < 0.05 and r = 0.76, p < 0.05, respectively) in the maze group. In an angiographic study, the mean left atrial maximal volume index in the maze group was approximately three times larger than that in the control group (117.5 +/- 24.3 mL/m2 versus 35.3 +/- 6.6 mL/m2 [p < 0.01]). The left atrial active emptying volume index was significantly smaller in patients in the maze group (7.2 +/- 2.5 mL/m2 versus 13.1 +/- 4.6 mL/m2 [p < 0.01]).

CONCLUSIONS

After the maze procedure performed concomitantly with a mitral valve operation in patients with a dilated left atrium, left atrial contraction is detectable but incomplete in the elderly.

[Repair of mitral valve prolapse by resection and sliding plasty]

There have been many techniques applied to the repair of mitral valve prolapse, and the method used in a particular case is usually selected according to the position and extent of the lesion. To simplify and standardize the technique of mitral valve repair, we have adopted the resection, sliding plasty and ring annuloplasty methods since December 1992. Of 10 consecutive surgical cases, 2 involved prolapse of the anterior leaflet, 1 the posteromedial commissural, and 7 the posterior leaflet. One patient with posterior leaflet prolapse required valve replacement due to dehiscence of the plastied site on the 3rd postoperative day, and one died because of sepsis. However, the remaining patients were doing well without mitral regurgitation at a mean of 20 months (range: 8-32) after the operation. The advantages of these techniques include easy adjustment of the height of the leaflet and a good chance of long-term durability, since the affected lesion is resected.

Human obese gene expression. Adipocyte-specific expression and regional differences in the adipose tissue

The obese (ob) gene, the mutation of which results in severe hereditary obesity and diabetes in mice, has recently been isolated through positional cloning. In this study, we isolated a full-length human ob complementary DNA (cDNA) clone and examined the tissue distribution of ob gene expression in humans. The nucleotide sequences of the human ob cDNA coding region were 83% identical to those of the mouse and rat ob cDNA coding regions. Analysis of the deduced amino acid sequences revealed that the human ob protein is a 166-amino acid polypeptide with a putative signal sequence and is 84 and 83% homologous to the mouse and rat ob proteins, respectively. Northern blot analysis using the cloned human ob cDNA fragment as a probe identified a single messenger RNA (mRNA) species 4.5 kb in size found abundantly in the adipose tissues obtained from the subcutaneous, omental, retroperitoneal, perilymphatic, and mesenteric fat pads. However, no significant amount of ob mRNA was present in the brain, heart, lung, liver, stomach, pancreas, spleen, small intestine, kidney, prostate, testis, colon, or skeletal muscle. The ob mRNA level in the adipose tissue varied from region to region even in the same individual. Furthermore, in the human adipose tissue, ob gene expression occurred in mature adipocytes rather than in stromal-vascular cells. This study is the first report of the elucidation of ob gene expression in human tissues, thereby leading to better understanding of the physiological and clinical implications of the ob gene.

Efficacy of long-term treatment with nipradilol, a nitroester-containing beta-blocker, in patients with mild-to-moderate essential hypertension

The effects of long-term treatment with nipradilol, a nitroester-containing beta-blocker, on casual and 24-hour blood pressures were studied in 70 patients with mild-to-moderate essential hypertension. Antihypertensive effects of nipradilol on casual blood pressure were observed in 68% of patients. Nipradilol reduced pulse rates, but no bradycardia was observed. The usefulness of nipradilol in the present study was 65%. The results of ambulatory blood pressure monitoring indicated that nipradilol reduced systolic blood pressure more than diastolic blood pressure, and reduced blood pressure during waking more than during sleep. These results suggest that nipradilol is a safe and useful long-term antihypertensive drug in both young and older patients with mild-to-moderate essential hypertension. When administered twice daily, nipradilol is effective throughout a 24-hour period.

Immunohistochemical study of p53 expression in cancer tissues from patients undergoing radiation therapy

Immunostaining using p53 monoclonal antibodies (p53(Ab-3) recognizes mutant type and p53(Ab-6) the wild type of p53 protein) was performed on frozen sections of biopsy specimens obtained before and during preoperative radiotherapy from 23 patients with head and neck squamous cell carcinoma. The positive staining rates of p53(Ab-3) before radiotherapy and at radiation doses of 4Gy, 10Gy and 20Gy were 30.0%, 38.9%, 25.0% and 6.25%, and those of p53(Ab-6) 10.5%, 11.8%, 5.0% and 0% respectively. The relationship between the immunohistochemical findings and antitumor effect at radiation dose of 20Gy was examined on the correspondent haematoxylin-eosin sections. In patients whose p53(Ab-3) stainings were positive at any doses of radiotherapy, the antitumor effect at the cumulative dose of 20Gy waas either remarkable or effective. Moreover, the frequency of the expression of mutant type p53 protein tended to increase in rather radiosensitive tumors. As for wild type p53 protein, there was no remarkable relationship between the staining of p53(Ab-6) and the antitumor effect.

Immunohistochemical demonstration of tenascin in human pituitary glands and adenomas

The expression of tenascin in 8 cases of normal fetal and adult human pituitary glands and in 51 cases of human pituitary adenomas was investigated immunohistochemically with the use of polyclonal antibodies against human tenascin. The immunohistochemical study demonstrated that tenascin is expressed in both fetal and adult normal epithelial cells of the anterior lobe of pituitary glands and in tumor cells of pituitary adenomas, which suggests that tenascin is synthesized by normal pituitary cells as well as by pituitary adenoma cells. Plurihormonal pituitary adenomas, especially those producing 4 or 5 different hormones, tended to show the highest incidence of positive immunoreactivity for tenascin, suggesting that tenascin may be involved in the aggressive behaviour of plurihormonal adenomas.

Comparative developmental toxicity of butyltin trichloride, dibutyltin dichloride and tributyltin chloride in rats

Butyltin trichloride (BT), dibutyltin dichloride (DBT) and tributyltin chloride (TBT) were compared for their developmental toxicity including teratogenic potential following administration during the susceptible period for the teratogenesis of DBT. Pregnant rats were given either BT at a dose of 1000, 1500 or 2000 mg kg-1, DBT at a dose of 10 or 15 mg kg-1 or TBT at a dose of 40 or 80 mg kg-1 by gastric intubation on days 7 and 8 of pregnancy. Although maternal toxicity occurred, as evidenced by a significantly increased maternal lethality at 1500 and 2000 mg kg-1 and decreased maternal weight gain at 1000 and 1500 mg kg-1, no significant increase in the incidences of postimplantation loss and malformed fetuses were observed after treatment with BT. Treatment with DBT resulted in a significantly lower maternal weight gain, lower fetal weight and higher postimplantation embryolethality. A significantly and markedly increased incidence of fetuses with malformations, such as exencephaly, cleft jaw, cleft lip, ankyloglossia, club foot, deformity of the vertebral column in the cervical and thoracic regions and of the ribs and ano- or microphthalmia, was observed in both groups treated with DBT. While treatment with TBT at 40 and 80 mg kg-1 caused a significantly decreased maternal weight gain and increased postimplantation embryolethality, no significantly increased incidence of malformed fetuses occurred. It could be concluded that BT, DBT and TBT are different in the susceptibility and spectrum of developmental toxicity.

Developmental toxicity evaluation of mono-n-butyl phthalate in rats

Mono-n-butyl phthalate (MBuP) was evaluated for developmental toxicity in Wistar rats. Rats were given MBuP by gastric intubation at 0, 250, 500 or 625 mg/kg on days 7-15 of pregnancy. Significant decreases in the maternal body weight gains and food consumption during pregnancy were found at 500 and 625 mg/kg. Significant increase in the incidence of postimplantation loss per litter and decreases in the number of live fetuses per litter and fetal weight were also detected at 500 mg/kg and above. The incidence of fetuses with malformations in the 500 and 625 mg/kg groups was higher than that in the control group. Cleft palate, deformity of the vertebral column and dilatation of the renal pelvis were frequently observed.

Application of a spray drying technique in the production of TRH-containing injectable sustained-release microparticles of biodegradable polymers

Copoly (dl-lactic/glycolic acid) microparticles for sustained release of a water-soluble drug (Thyrotropin releasing hormone: TRH) were prepared by a spray drying method. A higher entrapment ratio was achieved with the spray drying method with the in-water drying method. In order to avoid agglomeration of the microparticles, a double-nozzle spray drying method was designed using mannitol as an anti-adherent. The surface of the spray-dried microparticles was coated with mannitol, and the extent of agglomeration was decreased. Acetonitrile was the most suitable solvent for microencapsulation using the double-nozzle spray drying method because the initial burst of TRH from the microparticles during the first day was the smallest. When PLGA with a weight-average molecular weight of 14,000 was used, constant release of TRH continued for one month with a small initial burst. In conclusion, the production of biodegradable microparticles by the double-nozzle spray drying method appears to be an attractive alternative to conventional microencapsulation methods.

[A case of vascular leiomyoma in the larynx]

We report a recently encountered case of vascular leiomyoma in the larynx. The patient was a 76-year-old man with a chief complaint of hoarseness. Laryngoscopy revealed a bean-sized, reddish tumor with a smooth surface, suspended from the right vocal cord toward the subglottis. Its border was clear on MR imaging. Tracheotomy was performed under local anesthesia, and laryngomicrosurgery was then carried out under general anesthesia. The tumor was encapsulated and could be completely resected. Histological study indicated smooth muscule cell proliferation, especially around capillaries, and the tumor was diagnosed as a vascular leiomyoma. Our extensive survey of the literature revealed 20 reports of benign myogenic tumor of the larynx (9 cases of simple leiomyoma, 10 of vascular leiomyoma, and 1 of leiomyoblastoma), many of which occurred in the middle and advanced years. The patients consisted of 15 men and 5 women, including 9 male vascular leiomyoma patients of middle or advanced age. The site of occurrence was supraglottic in 12, glottic in 4 and subglottic in 4; no relation was observed with the histological picture, however. Treatment was surgical, and some cases also required tracheotomy depending on the site of occurrence and morphology.

Reappraisal of safety of endoscopic sphincterotomy for common bile duct stones in the elderly

BACKGROUND

Endoscopic sphincterotomy is the method of choice for elderly patients with common bile duct stones, even though these patients are poor operative risks. We undertook this study to analyze the operative risk factors for this age group.

METHODS

We compared specific problems of 182 patients aged 80 years or older and 921 younger patients who underwent endoscopic sphincterotomy for common bile duct stones.

RESULTS

Despite a higher frequency of periampullary diverticula in the elderly than in the younger patients (54% versus 36%, P < 0.001), the success rates of sphincterotomy were not different. The elderly patients required lithotripsy more often than did the younger ones (15% versus 4%, P < 0.001), and the necessity of stenting or nasobiliary drainage was greater in this group (9%) than in the younger group (5%, P < 0.05). This difference in the tactics between the older and younger groups was due to the greater number and size of stones, longer period of time for complete clearance of the common bile duct (13.5 versus 6.0 days, P < 0.01), and a greater percentage of patients with operative risks (55% versus 36%, P < 0.001). The elderly also had significantly greater overall morbidity compared with the younger patients (13% versus 7%, P < 0.005), frequency of acute cholangitis (8% versus 2%, P < 0.001), and mortality (1% versus 0%).

CONCLUSION

These results suggest that frequent stenting or nasobiliary drainage to prevent cholangitis or prompt stone removal by lithotripsy would be necessary in this group of patients.

Pancreatoduodenectomy for periampullary tumors: a univariate and multivariate analysis of the parameters influencing the morbidity, mortality, and survival rates

A total of 69 patients who underwent a pancreatoduodenectomy (PD) for a periampullary tumor in the Department of Surgery I, Kyushu University Hospital from January 1980 to December 1993 were analyzed in order to identify the parameters influencing the morbidity, mortality and survival rates. Anastomotic leakage was seen in 15 of the 69 patients; at the site of a pancreatojejunostomy in nine and at the site of a biliojejunostomy in six. A univariate analysis of complications based on 16 factors showed that major intraabdominal complications (anastomosis leakage and intrabdominal hemorrhage and abscess) were significantly affected by blood loss (> or = 1600 g vs < 1600 g, p < 0.05). Two of the 69 patients died within one month after PD, and the mortality rate was 3%. A univariate analysis of the survival rates of the 69 patients based on the 16 parameters showed that a history of jaundice, the serum level of albumin, and the nature of disease (i.e. malignant or benign) significantly influenced the survival rates (p < 0.05). The year of operation, the age of the patients, the serum level of total bilirubin, the operation time and the operative blood loss were not significant variants. A multivariate Cox regression analysis on these three profound factors showed that malignant disease significantly influenced the clinical course of patients with PD (p < 0.01). With proper patient selection and operative techniques, PD can thus be safely performed for a wide variety of diseases, in virtually any age group.

The role of renal dopamine in the reduction of high blood pressure by beta 1-selective beta-blocker with intrinsic sympathomimetic activity in spontaneously hypertensive rats

The present experiments were undertaken to clarify the difference of renal dopamine production from beta 1-selective beta-blocker with and without intrinsic sympathomimetic activity (ISA). Either beta-blocker with ISA, celiprolol (100 or 300 mg/kg/day; CEL-100 or CEL-300) or beta-blocker without ISA, atenolol (50 mg/kg/day; ATE-50) was administered to the SHR from 19 to 26 weeks. Degrees of lowering blood pressure in CEL-300 SHR and in ATE-50 SHR were similar, but decrease in heart rate was significantly less in CEL-300 SHR than in ATE-50 SHR. Urine output, which was significantly less in control SHR than in control WKY, was significantly greater in CEL-100 SHR and CEL-300 SHR, but not in ATE-50 SHR. Urinary excretions of noradrenaline (u-NA) and dopamine (u-DA) were significantly higher in control SHR than in control WKY and a comparable u-DA/u-NA ratio was found in these two groups. U-DA and the ratio of u-DA/u-NA were significantly elevated in CEL-100 SHR and CEL-300 SHR, but not in ATE-50 SHR. There was a significant positive correlation between u-DA/u-NA ratio and urine output and a significant negative correlation between the ratio of u-DA/u-NA and change of blood pressure in control SHR, CEL-100 SHR and CEL-300 SHR. These results suggest that an enhancement of renal dopamine production by ISA (beta 2 stimulation) of beta 1-selective beta-blocker may contribute, at least in part, to the antihypertensive effect of this drug.

Microvessel quantitation in invasive breast cancer by staining for factor VIII-related antigen

The clinical importance of microvessel quantitation as a prognostic indicator in invasive breast cancer was examined. This study included 155 patients with invasive breast cancer, with a median follow-up of 82 months. Microvessels were identified by immunohistochemical staining for factor VIII-related antigen in formalin-fixed, paraffin-embedded primary tumours. For each tumour, microvessels were counted within a 200 x magnification field in the area of highest microvessel density. Microvessel counts (MVCs) had no correlation with tumour size, lymph node status or histological grade. When patients were classified by MVC, higher counts were associated with shorter disease-free survival and overall survival (P < 0.025 and P < 0.01 respectively). Multivariate analysis showed that MCV is an independent prognostic factor. Microvessel quantitation may be a useful predictor for identifying breast cancer patients at high risk for relapse and death.