Squamous cell carcinoma originating in the parotid gland: MRI features with histopathological correlation.

AIM: To report the magnetic resonance imaging (MRI) and corresponding histopathological features of squamous cell carcinoma (SCC) originating in the parotid gland. MATERIALS AND METHODS: The MRI images of seven patients with histopathologically proven SCC originating in the parotid gland were reviewed retrospectively, with an emphasis on tumour size, shape, contour definition, extraparotid infiltration, signal characteristics, and the presence of central necrosis. These were correlated with the microscopic findings of the surgical specimens. RESULTS: The tumours ranged in size from 3.9-7 cm (mean 4.7 cm). All tumours had an ill-defined margin with extraparotid infiltration, which seemed to reflect the invasive growth of the tumour cells on histopathological examination. The solid portions of the tumours showed predominantly low to intermediate signal intensities on T2-weighted images, which seemed to reflect the high cellularity, intercellular bridges, and/or keratin pearl formation observed at histopathological examination. Five of the seven tumours had central necrosis. CONCLUSION: A relatively large tumour with central necrosis is a useful imaging feature of SCCs originating in the parotid gland, in addition to the well-recognized indicators of parotid malignancy, such as an ill-defined margin, extraparotid infiltration, and low to intermediate signal intensity on T2-weighted images.

Therapeutic effects of imidapril on cerebral lesions observed by magnetic resonance imaging in malignant stroke-prone spontaneously hypertensive rats.

OBJECTIVE: Magnetic resonance imaging (MRI) was used to investigate the therapeutic effects of imidapril, a newly synthesized angiotensin converting enzyme (ACE) inhibitor, on cerebral stroke lesions. DESIGN: Pretreatment with ACE inhibitors is known to prevent stroke in stroke-prone spontaneously hypertensive rats, prolonging their lifespan. Malignant stroke-prone spontaneously hypertensive rats (M-SHRSP) were treated with imidapril after the onset of stroke. METHODS: M-SHRSP with proved stroke were divided into two groups. One group received 40 mg/kg per day imidapril and the other group was used as a control. For 4 weeks, neurological symptoms were scored daily, and MRI images were taken and scored once a week. RESULTS: In the control group the MRI score for cerebral lesions increased during the experiment, and seven out of eight control rats died within 17 days. In rats treated with imidapril the major finding was that imidapril rapidly ameliorated the damage to the blood-brain barrier and resolved brain oedema within 1 week. At the same time the neurological symptoms observed after stroke disappeared. Furthermore, none of the rats treated with imidapril showed recurrence of stroke, and their survival rate was improved. CONCLUSION: These results suggest that imidapril has therapeutic effects on stroke lesions, as well as prophylactic effects on the recurrence of stroke.

Chronic treatment with captopril, SQ29,852, hydralazine and a 33% fish meal diet in malignant stroke-prone spontaneously hypertensive rats.

Malignant stroke-prone spontaneously hypertensive rats (M-SHRSP) are a useful animal model for studying juvenile malignant hypertension. Using M-SHRSP males, the effects of SQ 29,852 [(S)-1-[6-amino-2-[[hydroxy (4-phenylbutyl) phosphinyl]oxy]-1-oxohexyl]-L-proline; 30-40 mg/kg per day], captopril (30-40 mg/kg per day), hydralazine hydrochloride (10-15 mg/kg per day) and a 33% fish meal diet on the prevention and therapy of malignant hypertension were examined. Drugs and diet were given separately, beginning at weaning, maturity or adulthood. Observed effects included antihypertension, prolonged life span and prevention and/or reversal of angionecrosis. Each treatment resulted in an antihypertensive effect, but some adult rats seemed treatment-resistant. SQ 29,852 was the most effective treatment for reducing blood pressure. The life span of animals in the treated groups was extended significantly beyond that of the controls. In particular, those rats treated with either captopril or SQ 29,852 lived in excess of 500 days. This included not only those in which treatment resulted in a lowering of blood pressure, but also those whose severe hypertension was not so reduced. Angionecrosis was observed in the organs of many of the non-treated animals, including the brain, heart, kidneys and testes. Both hydralazine and the fish meal diet had a limited effect, if any, on the prevention or reversal of angionecrosis. In contrast, almost none of the rats given either captopril or SQ 29,852 showed cerebrovascular lesions or angionecrosis of the brain, heart and kidneys; angionecrosis in adult M-SHRSP kidneys disappeared within 10 or 18 days after the initiation of SQ 29,852 or captopril, respectively. This data seems to support a possible role for these two drugs not only in prevention, but also in repair, of angionecrosis independent of markedly high blood pressure in M-SHRSP. Based on our overall observations, SQ 29,852 was seen as the most effective of the treatments studied.

Elevated plasma levels of beta-thromboglobulin and platelet factor 4 in patients with rheumatic disorders and cutaneous vasculitis.

The efficacy of plasma levels of beta-thromboglobulin (beta-TG) and platelet factor 4 (PF4) as markers of the presence and activity of vasculiditic processes in rheumatic diseases were evaluated, first by serial measurement of their levels in a patient with rheumatoid arthritis and a chronic leg ulcer in the course of treatment, and second in 11 patients with rheumatoid arthritis without cutaneous vasculitis, and in nine patients with a variety of rheumatic diseases with cutaneous vasculitis. In the former, plasma levels of beta-TG and PF4 were elevated and slowly reduced in parallel with healing, raised again after relapse, and normalized after disappearance of the leg ulcer. In the latter, both plasma levels were elevated in all of the nine patients with cutaneous vascular lesions and in one of the 11 patients rheumatoid arthritis without skin lesions. Levels of beta-TG and PF4 may be useful to estimate the presence of vascular lesions in rheumatic disorders.

Establishment and use of the M strain of stroke-prone spontaneously hypertensive rat.

An inbred strain of stroke-prone spontaneously hypertensive rat, the M-SHRSP, was established by brother-sister breeding of selected SHRSP for 24 generations while administering apresoline. Compared with SHRSP, the M-SHRSP shows an earlier rise in blood pressure, plasma renin activity (PRA) and cerebrospinal fluid (CSF) pressure, and somewhat changed cerebrovascular lesions. Crosses and back-crosses, using M-SHRSP, Wistar-Kyoto rats (WKY), spontaneously hypercholesterolaemic (SHC) rats and their hybrids produced colonies with various blood pressure levels and hypercholesterolaemia. Continued successive selective brother-sister breeding of M-SHRSP and SHC hybrids produced a colony with severe hypertension and marked hypercholesterolaemia. Streptozotocin diabetes was induced in an M-SHRSP and SHC hybrid (TC), from which diabetic TC was successively bred to the fifth generation. While each generation was hypertensive and showed a decrease in islet B-cells, symptoms of lasting glycosuria were first observed in the fourth generation among those given a high alpha-corn starch (75.7%) diet.

Long-term therapeutic effects of ace inhibitor and calcium antagonists on hypertensive vascular lesions in M-SHRSP.

1. Our results indicate that the drugs used in this study are very effective in malignant hypertension therapy. 2. For M-SHRSP treated with highly effective antihypertensive drugs, if blood pressure remains under 200 mmHg over the long-term, the structures of the small arteries and/or arterioles stay as well preserved as they do in WKY. 3. For M-SHRSP treated with drugs with a lower antihypertensive effect, the occurrence of cerebrovascular lesions and angionecrosis in the various organs are suppressed significantly, even though blood pressure remains over 250 mmHg over the long-term. Based upon effect alone, there is no difference between ACEI and a calcium antagonist. However, inhibition of the proliferation of vascular smooth muscle cells is more potent in the former than in the latter. 4. These results suggest that ACEI might have the potential to suppress smooth muscle cell proliferation independent of high blood pressure.

In vivo differentiation of edematous changes after stroke in spontaneously hypertensive rats using diffusion weighted MRI.

Apparent diffusion coefficients (ADCs) of tissue water were determined in chronic brain lesions of a rat stroke model, the stroke-prone spontaneously hypertensive rat, and compared with histology. ADCs increased in the order normal < edema < gliosis < cyst. The differences between individual groups were statistically significant. The increase in ADC is thought to mainly reflect a relative increase in the extracellular space in brain tissue. ADC may be a new parameter for tissue characterization.

Differentiation of chronic lesions after stroke in stroke-prone spontaneously hypertensive rats using diffusion weighted MRI.

Apparent diffusion coefficients (ADCs) of tissue water were determined in chronic brain lesions of a rat stroke model, stroke-prone spontaneously hypertensive rats and compared with histology. ADCs increased in the order control < edema < gliosis < cyst. The differences between individual groups were statistically significant. The increase in ADC is thought to mainly reflect a relative increase in the extracellular space in brain tissue. ADC values may be a clinically useful parameter for tissue characterization.

Temporal and spatial properties of slow waves in the electroencephalogram of spontaneously hypertensive rats.

1. Electroencephalogram (EEG) of stroke-prone spontaneously hypertensive rats (SHRSP) and M(malignant)-SHRSP were analysed for excitability changes in the cerebral neuronal circuit using power spectral comparisons. 2. EEG in hypertensive SHRSP and M-SHRSP showed the emergence of slow wave bursts parallel to the development of hypertension. 3. These bursts were composed of spikes and sharp waves, and became dominant in the later stages of hypertension. 4. Bursts were interposed by a silent period indicating a strongly depressed state of neuronal activities. The ratio of the periods of the depressed to the burst increased with the progress of the hypertension. 5. A shift of the major component toward a lower frequency band also indicated decreased cerebral activity.

Electroencephalographic evaluation of the therapeutic efficiency of antihypertensive agents on M-SHRSP.

1. In order to evaluate the therapeutic effects of antihypertensive agents on malignant hypertension in M-SHRSP, EEG were performed as a non-invasive, therapeutic index. 2. Under pentobarbital anaesthesia, the EEG pattern of rats with severe hypertension and/or cerebrovascular lesions showed alternate short-active and long-depressive phases with spike and sharp waves. 3. When M-SHRSP were treated with an angiotensin converting enzyme inhibitor (SQ 29,852) or a calcium antagonist (manidipine), the depressive phases became shorter and active phases longer. These changes were more prominent in manidipine treated rats than in SQ 29,852 treated rats. 4. The EEG spike- and sharp-wave complex seems to be a convenient index for evaluating cerebrovascular lesions and cerebral activity in M-SHRSP.

Memory deficit accompanying cerebral neurodegeneration after stroke in stroke-prone spontaneously hypertensive rats (SHRSP).

Memory performances of SHRSP with chronic stroke were examined on the three-panel runway task in addition to the histological evaluation and magnetic resonance imaging (MRI) of the brain. After recovery from the neurological symptoms with stroke. SHRSP were subjected to acquisition training on the memory tasks, and they exhibited both a delay and a persistent impairment of acquisition on the memory tasks, compared to the non-stroke SHRSP. T2-weighted MRI with the stroke SHRSP suggested marked edematous formation in the cortex, caudate putamen and/or thalamus, preferentially in the frontal and/or occipital cortex. The histological evaluation showed edematous degeneration such as edema, gliosis and cyst preferentially in the cortex, but no degeneration in the hippocampus. Thus, SHRSP with chronic stroke was found to exhibit impairment of learning and memory, which may be due to the cortical edematous degeneration.

Therapy and prevention of hypertension of M-SHRSP.

M-SHRSP rats appear to be a useful animal model for studying juvenile human malignant hypertension. Using M-SHRSP, the present study was conducted. Drugs selected for use were captopril, SQ 29,852 and hydralazine hydrochloride. The rats were also fed a 33% fish meal diet. When given separately, all three drugs were shown to be anti-hypertensive. However, using the fish meal diet combined with hydralazine was more effective than were any of the drugs given separately, while the effect of hydralazine combined with captopril or SQ 29,852 was even greater than that of the combined fish meal diet and hydralazine treatment. Some rats treated with captopril or SQ 29,852 separately were resistant to treatment, however even for these rats life spans were significantly prolonged and hypertensive vascular lesion incidence rates were drastically lowered. It was also found that even such vascular lesions as angionecrosis seemed to disappear with captopril or SQ 29,852 treatment.

Epidermoid cyst originating from an intrapancreatic accessory spleen.

Pancreatectomy in a 45-year-old woman showed, after pathologic analysis, an epidermoid cyst originating from an intrapancreatic accessory spleen. This mass consisted of parenchymal and cystic components. It is important to note the relation between the splenic parenchyma and the parenchymal component of the mass for the differential diagnosis of a cystic mass in the pancreatic tail.

Multiple nonfunctional pancreatic islet cell tumor in multiple endocrine neoplasia type I. A case report.

A case of multiple nonfunctional pancreatic islet cell tumor in multiple endocrine neoplasia type I (MEN I) is reported. The patient was a 41-year-old woman who had a past history of thyroid cancer (papillary carcinoma) and hyperparathyroidism due to parathyroid adenoma. Later, a nonfunctional pituitary tumor and five nonfunctional pancreatic tumors were found simultaneously and the patient was finally diagnosed as having MEN I. Following surgical enucleation, the pancreatic tumors were histopathologically diagnosed as benign islet cell tumors. One of them (tumor 3) exhibited a solid nodular pattern while the others showed gyriform patterns. They were divided histochemically and immunohistochemically into three types: two (tumors 1 and 2) produced a single hormone (glucagon), one (tumor 3) produced five (insulin, glucagon, somatostatin, gastrin and pancreatic polypeptide) and the remaining two (tumors 4 and 5) produced two (glucagon and pancreatic polypeptide). Electron microscopically, three types of endosecretory granules were found in the tumor cells of tumor 3 but only one type was found in tumor 4. However, in the tumor 4 extract, glucagon, pancreatic polypeptide, C-peptide, somatostatin, vasoactive intestinal peptide and growth hormone releasing factor were detected by radioimmunoassay. These findings suggest that these pancreatic tumors were both multicellular and multihormonal.

Ocular fundus changes in malignant or precocious stroke-prone spontaneously hypertensive rats after administration of antihypertensive drugs.

1. Malignant or precocious stroke-prone spontaneously hypertensive rats (M-SHRSP) showed hypertensive ocular fundus changes with severe hypertension, but various anti-hypertensive drugs given over a proper period improved funduscopic findings. 2. We treated a M-SHRSP with SQ29,852 (an angiotensin converting enzyme inhibitor, ACEI) or manidipine (a calcium antagonist) and observed hypertensive vascular changes in the fundus. 3. The M-SHRSP treated with anti-hypertensive drugs lived longer and the hypertensive fundic changes improved in both groups. But there were some differences of histochemical staining reaction on the endothelial cell-surface and mucopolysaccharides accumulations between the treated group of ACEI and the group treated with the calcium antagonist. 4. In the treated group with calcium antagonist, the anionic ion functions of the endothelial cell-surface were impaired and organic retinal or choroidal damages appeared to have deteriorated.

[MR imaging of cerebral lesions accompanying stroke in stroke-prone spontaneously hypertensive rats].

Cerebral lesions accompanying stroke in male stroke-prone spontaneously hypertensive rats (SHRSP, n = 10) were examined by both magnetic resonance imaging (MRI) and histological evaluation. T2-weighted MR images (T2-WI), taken 1-2 days after animals showed behavioral hyperactivity, indicated hyperintense regions in the occipital cortex, caudate putamen and/or thalamus. The areas of hyperintensity on T2-WI corresponded to neurodegenerative regions including edema, gliosis, and softening of the tissue. T1-weighted images (T1-WI) did not show any hyperintense regions. However T1-weighted images enhanced by the contrast media Gd-DTPA (Gd-T 1-WI) showed hyperintense spots within some of the hyperintense areas on T2-WI, which exhibited neurodegenerative regions such as thrombus, angionecrosis and hemorrhage in addition to the edematous formation. The hyperintense areas on Gd-T1-WI were smaller than those on T2-WI. In some animals, hypointense spots on T2-, T1- and Gd-T1-WI were found within the hyperintense areas, which corresponded to clots. Extensive histological examination did not reveal any additional cerebral degeneration which had not been detected on the MR images. These findings indicate that MRI is useful for detecting and differentiating various types of cerebrovascular disease in this model.