Scanning electron microscopic study of Warthin's tumor

Three cases of Warthin's tumors were studied with a scanning electron microscope. The free surface of the epithelium was composed mainly of round or ovoid dome-like structures bearing microvilli and apocrine protrusions. Ciliated epithelial cells were detected in 2 of the tumors. The tumor epithelium encircled various amounts of cellular debris resembling degenerate lymphoid cells. A few tiny cystic spaces were also found. Within the lymphoid stroma, tightly packed lymphocytes, a meshwork of reticulum cells and medullary cord-like structures were observed. Our findings support the concept that Warthin's tumors develop from heterotopic salivary gland ducts within pre-existing lymph nodes.

Stimulatory effect of cisplatin on production of lipid peroxidation in renal tissues

Cisplatin (cis-diamminedichloroplatinum II), an anticancer chemotherapeutic agent with the dose-limiting side effect of nephrotoxicity, caused a statistically significant increase in lipid peroxidation, monitored by measuring the production of malondialdehyde, in rat kidney 72 hr after injection. Treatment of rats beforehand with the antioxidant alpha-tocopherol or N-N'-diphenyl-p-phenylenediamine (DPPD) effectively decreased such peroxidation. DPPD was a more effective inhibitor than alpha-tocopherol, since it is known for its ability to scavenge free radicals more powerfully. The ability of renal cortical slices to accumulate p-aminohippurate (PAH) was examined as a biochemical parameter that would change in nephrotoxicity. The ability to accumulate PAH by the incubated slices decreased 72 hr after administration of cisplatin. The pretreatment with DPPD prevented the decrease in PAH accumulation in the slices from rats treated with cisplatin. Structural changes of the renal proximal tubule caused by cisplatin, analyzed in a transmission electron microscope, were also prevented by the pretreatment with DPPD. The results suggest that cisplatin affects renal tissues in which free radicals generated by cisplatin may interact with membrane lipids to cause the production of lipid peroxidation, which affects both cellular structure and function.

Colorectal goblet cell sialomucin heterogeneity: its relation to malignant disease

Mucus secreted by colorectal cancer differs in three respects from that produced normally: an overall reduction, a loss of O-acetyl substituents in sialic acid, and an increase in neutral mucin. Similar changes have been reported in apparently normal mucosa bordering colorectal cancer. "Normal" left sided colorectal mucosa from 32 patients with rectal cancer was studied. Each case was matched by age and sex to a patient with diverticular disease and a patient with irritable bowel syndrome. Twenty five patients with right sided cancer were matched to patients with Crohn's disease. Sections were stained with mild periodic acid Schiff (mPAS) (selectively stains N-acetyl sialic acid lacking in O-acetyl group) and other closely related techniques. Reactions were graded negative, weak, and intense. An intense reaction was found in 9% of cases; there was no difference between the various matched groups. Phenylhydrazine interposition failed to block the mPAS effect, indicating that a positive result was due to a deficiency of sialic acid with O-acetyl substituents rather than neutral mucin. Different staining patterns in left and right colon were probably due to differing ratios of total sialic acid:fucose. These findings indicate a hitherto unsuspected colorectal goblet cell sialomucin heterogeneity within the general population, but no association with neoplastic disease is apparent.

Participation of liver aldehyde oxidase in reductive metabolism of hydroxamic acids to amides

The liver enzyme responsible for the reduction of aromatic and heterocyclic hydroxamic acids to the corresponding amides was investigated with salicylhydroxamic acid, benzohydroxamic acid, anthranilhydroxamic acid, and nicotinohydroxamic acid. Rabbit liver cytosol exhibited significant reductase activities toward the hydroxamic acids under anaerobic conditions when supplemented with an electron donor of aldehyde oxidase. Similarly, rabbit liver aldehyde oxidase reduced these compounds to amides in the presence of its own electron donor, indicating that the reductase activities observed in the liver cytosol are due mainly to the cytosolic molybdoflavin enzyme. Furthermore, a significant reduction of salicylhydroxamic acid and nicotinohydroxamic acid was also observed, when an electron donor of aldehyde oxidase was added, with liver cytosols from hamsters, guinea pigs, rats, and mice. The cytosolic reductase activities toward salicylhydroxamic acid were markedly inhibited by menadione, an inhibitor of aldehyde oxidase.

Modification of cisplatin toxicity by antioxidants

cis-Diamminedichloroplatinum II (cisplatin) is a potent anticancer chemotherapeutic agent. The major limitation in its use is nephrotoxicity, caused by an unknown mechanism. Injection of cisplatin into rats caused a decrease in body weight and an increase in blood urea nitrogen (BUN). These effects were modified by giving a radical scavenger, alpha-tocopherol, before the cisplatin injection. N-N'-diphenyl-p-phenylenediamine, another powerful radical scavenger, also attenuated the increase in BUN induced by cisplatin. These results suggest that the toxic effects of cisplatin may be related to free radical induced damage.

Small "flat adenoma" of the large bowel with special reference to its clinicopathologic features

Thirty-three small "flat adenomas," not more than 1 cm in diameter, were collected from surgically and colonoscopically removed specimens, and their colonoscopic and histologic characteristics were described. There were 14 adenomas with mild atypia, five with moderate atypia, 14 with severe atypia (or focal carcinoma limited to the mucosa). The grade of atypia seems to increase with the size of lesions, and these lesions were assumed to play an important role in the adenoma-carcinoma sequence. The importance of recognizing the presence of these small "flat adenomas" in everyday practice is stressed.

Evidence for in vivo effect of lithium on p-aminohippurate transport in rat kidney, preliminary study

We examined the effect of lithium on rat renal handling of p-aminohippurate (PAH) and accumulation of organic ions by rat kidney cortical slices. When infused intravenously with lithium at the rate of 0.13 mmoles/kg/min, decreased renal clearance of PAH as well as no significant changes in glomerular filtration rate and plasma PAH level was observed at the first clearance period during lithium infusion. As we expected, tubular secretion of PAH also was decreased significantly by the infusion of lithium. Therefore, it is suggested that the decrease in the clearance of PAH was due to the decrease in the tubular secretion of PAH. After four days of injections with lithium (4 mmoles/kg, i.p., once a day), a significant decrease in PAH accumulation in the slices was detected. No inhibition of tetraethylammonium accumulation was observed. Lithium pretreatment did not alter water content and extracellular space of the slices. The results suggest that lithium selectively inhibits the organic anion transport system in kidney with the in vivo treatment and follows our previous work in which we showed the in vitro effect of lithium on organic anion accumulation in the slices.

Studies on the absorption of sodium guaiazulene-3-sulfonate. I

From the view points of safety and efficacy of sodium guaiazulene-3-sulfonate (GAS) after oral cavity administration, the absorption behavior of GAS was investigated in rats and rabbits and following results were obtained. 1) GAS was absorbed not from oral cavity but from nasal cavity in rats and rabbits. 2) The in situ perfusion experiments revealed the existence of dose-dependent specific absorption mechanism in the rat small intestine. 3) GAS was absorbed from neither the rat stomach nor the rectum. These facts reveal that GAS transfers into the systemic circulation only through the small intestine after the clinical application to the oral cavity. And these absorption characteristics of GAS are suited for its direct action on the inflamed oral mucosa. When GAS is administered into the oral cavity, the safety is at least the same as that obtained after oral administration.

Inhibitory effect on lithium on p-aminohippurate transport in rat kidney cortex in vitro

The effect of lithium on p-aminohippurate (PAH) transport was studied using slices and basolateral membrane vesicles prepared from rat kidney cortex. The addition of lithium in concentrations ranging from 0.5 to 5 mM caused a concentration-dependent inhibition of PAH accumulation in the slices. Lithium inhibited PAH accumulation in the slices, not only during the rapid uptake period (after 10 min) but also during the approach to equilibrium (after 30 min). The effect of lithium (2 mM) in the slices was irreversible. The inhibitory effect of lithium was not the result of changes in the water distribution and the concentrations of ATP, sodium and potassium in the slices during incubation. The effect of lithium on the kinetic parameters for PAH accumulation was to decrease Vmax, while apparent Km remained constant. There was no lithium effect on the efflux of PAH from the slices back into the incubation medium, indicating that lithium inhibited PAH influx to the kidney cell. No evidence was obtained to indicate that lithium (1 mM) directly affected PAH uptake by isolated basolateral membrane vesicles. These results suggest that lithium seems to affect metabolism linked to the carriers for PAH transport other than ATP production and sodium gradient and then seems to decrease the mobility of the carriers in the membranes.

Scanning electron microscopic study of odontogenic keratocysts

Three odontogenic keratocysts were examined with a scanning electron microscope (SEM) on their surface cells, prickle cells, basal cells, and the epithelial-connective tissue interface. The microridges of the surface cells had a short, discontinuous, branched or beaded appearance. Intracellularly, the flattened keratinized cells formed a network consisting of delicate microfilaments. The prickle cells had numerous cytoplasmic projections and a large round nucleus that occupied most of the cytoplasm. The basal cells had two types of cytoplasmic process and a large oval polarized nucleus. The epithelium and the lamina propria were connected by a fibrous and fibrillar network.

[Gastrinoma: diagnosis and management of Zollinger-Ellison syndrome]

Diagnosis and management of Zollinger-Ellison syndrome (ZES) do not appear to be established even today. In the present study, 143 cases of ZES (including 12 of author's experience) were collected from Japanese literature and analyzed, and diagnosis and management were discussed. (1) Although 43% of patients showed high gastrin level (greater than or equal to 500pg/ml), it is worth to be stressed that gastrin level was below 300pg/ml in 29% of patients. (2) Secretin provocation test was essential for diagnosis and particularly useful for detecting ZES with low gastrin level. (3) Angiography and/or blood samplings of PTPC were widely used for localizing gastrinoma but the informations thus obtained were not always of help for complete removal of tumors since malignant or multiple gastrinomas were frequent. (4) An aim of management for ZES consists of complete removal of tumor but it is not always feasible. Therefore, removal of target organ (total gastrectomy) should be routinely added for long-term cure. (5) Value of chemical gastrectomy (H2-receptor antagonist) is still a matter of pros and cons but substantial value of this drug should be considered adjunct to surgery.

Clinicopathological study of white spots of the colonic mucosa around polyps, with special reference to the endoscopic diagnosis of invasive carcinoma

White spots were observed on the mucosa immediately adjacent to polyps and carcinomas; the majority of the polyps proved to be carcinoma in situ or had invasive carcinoma. The white spots consisted of accumulations of foamy cells with features similar to muciphage.

Histopathologic comparison of colorectal adenomas in English and Japanese patients

Histopathologic comparison of colorectal adenomas removed at St. Mark's Hospital, London, England, and those removed at the University of Tokyo, Japan was performed. There were 1242 lesions in the St. Mark's series and 310 in the University of Tokyo series. All adenomas were removed either by colonoscopic polypectomy or hot biopsy. The indications and methods of colonoscopic removal were similar in the two series. Age distribution of the patients showed a younger peak incidence in the University of Tokyo series compared with the St. Mark's patients. The percentage of adenomas larger than 1 cm, of tubulovillous or villous type, and with moderate or severe dysplasia were greater in the St. Mark's series than in the University of Tokyo series. Percentages of adenomas with mild, moderate, or severe dysplasia in each category of size did not differ between the two series. In view of the fact that there is a high colorectal cancer risk in England and medium cancer risk in Japan, our results give further epidemiologic support to the concept of the adenoma-carcinoma sequence.

Diverticular disease of the colon in Japan. A review of 615 cases

Of 615 patients with diverticular disease of the colon, 429 had diverticula in the cecum and ascending colon, 98 in the sigmoid and descending colon and 88 in both the right- and left-side colon. The right-sided type was more common in younger people and more predominant in men, whereas the left-sided type was more common in the elderly and showed no difference in numbers between men and women. More than 50 per cent of patients were asymptomatic and 25 per cent complained of disturbed bowel function. The frequency of diverticulitis was not related to location, but to the number of diverticula. Seventy-seven were complicated by acute inflammation (right-sided diverticulitis, 61, and left-sided diverticulitis, 16). Many patients with right-sided diverticulitis improved with medical treatment and the operative procedure of choice was drainage of the inflamed area with supplemental appendectomy.

A necessary and sufficient condition for a picture to represent a polyhedral scene

As Shapira pointed out, a theorem by the author on line drawings of polyhedral scenes was not accurate. The present paper shows that the validity of the theorem is attained by a slight revision of the formulation.

Diffusion coefficient of 36Cl in silver chloride

Diffusion coefficient of 36Cl in silver chloride was revealed to be about 1 x 10(-10)-4 x 10(-11) cm2 . s-1 in the range of 400 degrees C-200 degrees C by means of radioactive tracer measurements. Activation energy for diffusion was calculated about 0.13 eV. These results were different from those obtained by Maurer and Compton.

Motility study in right sided diverticular disease of the colon

Intraluminal pressure in the ascending colon of 13 patients with right sided diverticular disease and 10 of normal subjects was studied with catheter-tip transducer inserted through colonoscopes. In the resting state the colonic motility index of patients with diverticular disease was greater than that of the controls. After intravenous injection of neostigmine methylsulphate higher pressure waves were more frequently observed in patients with diverticular disease than the controls, and the colonic motility index of patients was much greater than that of the controls with statistical significance. From these observations it is suggested that high intraluminal pressure and the abnormal motility in the ascending colon plays an important role in the pathogenesis of right sided diverticular disease.