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Biomedical subjects

S W How

Publications and source records attributed to S W How.

At least 19 recordsLinked to original sources

Localization of HPV-16 DNA sequence in CaSki cells by electron microscopic hybridocytochemistry.

We investigated the HPV-16 DNA sequence in the CaSki cervical carcinoma cell line by electron microscopic hybridocytochemistry using biotinylated HPV-16/18 probes. At the light microscopic level, reaction product of hybridized HPV-16 DNA sequence was not seen in the cytoplasm but appeared as spots or rods randomly distributed in the nuclei. By electron microscopy, reaction product was seen aggregated in several regions in the nuclei. Most of the stained areas did not reveal particular architecture but showed part of the chromatin structure. In other nuclei, reaction product was observed to be associated with strings of loop-like structure, and some stained loops were seen to be connected directly to the nuclear filamentous chromatin structure. The skeletonized images of hybridized HPV-16 DNA in the nuclei were illustrated by computerized image analysis. In conclusion, we have demonstrated the HPV-16 DNA sequence in the nuclei of CaSki cells by electron microscopy. The identification of stained areas localized only in the chromatin suggests an integrated form of HPV-16 DNA sequence in the cells. This method could be used to identify an integrated or episomal form of viral DNA in the virus-containing cells.

Biotin

Cardiac metastasis of hepatocellular carcinoma mimicking pericardial effusion on radionuclide angiocardiography.

A 51-year-old man presented with exertional dyspnea for two months. He had a history of hepatocellular carcinoma that was totally resected three years earlier. Radionuclide angiocardiography disclosed a large photopenic area separating the heart from the liver, and lung blood pools mimicking a large pericardial effusion. Echocardiography and magnetic resonance imaging of the heart, however, showed extensive tumor infiltration of the myocardium of both ventricles. Endomyocardial biopsy confirmed the diagnosis of metastatic hepatocellular carcinoma. There was no evidence of recurrent hepatoma in the liver.

Carcinoma, Hepatocellular

Investigation into allergic response in patients with chronic sinusitis.

We attempted to investigate the role of nasal allergy in sinusitis to elucidate whether it results from an immediate-type allergic reaction of the sinus mucosa or from allergic edema-induced sinus ostial obstruction. Forty-two patients with chronic sinusitis were selected for allergen skin tests, measurements of serum total and specific IgE, and sinus tissue-specific IgE. The data were then correlated to examinations of nasal mucosal scrapings and histopathology of the sinus mucosa. We found that serum levels of total IgE and house dust mite-specific IgE antibodies were significantly higher in patients (n = 12) allergic to house dust than in the nonatopics (n = 30; p less than 0.0001). There was no difference in the sinus tissue-specific IgE antibody. Eosinophils and basophilic cells in epithelial scrapings from the inferior turbinates, assessed by Hansel staining, were high in 66.7% and 50% of the atopic patients, respectively, and 36.7% and 26.7% of the nonatopics, respectively. The rates were influenced by the existence of infection and nasal polyps. The increase in eosinophils, mast cells and plasma cells, assessed by histopathologic examination, were not prevalent in the sinus mucosa of atopic patients. It is concluded that nasal allergy may be a predisposing factor to sinusitis and that the pathologic change of the sinus mucosa is mainly secondary, due to sinus ostial obstruction.

Adult

Bizarre parosteal osteochondromatous proliferation of the phalanx: report of a case.

The bizarre parosteal osteochondromatous proliferation of the hand and foot is a benign lesion which occasionally may mimic osteochondromas, chondrosarcomas or osteosarcomas clinically, radiologically and histopathologically. This rare benign entity should be recognized in order to avoid unwarranted destructive therapy. The authors report a case of this disease and discuss the differential diagnosis and the relevant features of this disease entity. A 27-year-old female patient suffered from a painful swelling at the proximal middle phalanx of the right middle finger for five months. The lesion was excised but the residual lesion developed a distinct parosteal growth by radiologic studies one-and-a-half years later. The patient underwent reexcision of the lesion twice. No recurrence was noted 11 months following the last excision. Histopathologically, the first specimen contained bizarre chondrocytes. The recurrent nodular tumors, submitted in the second and third operations, were composed of cancellous bone with fatty marrow and a few marrow elements, and focally capped by cartilage. The adjacent soft tissue contained proliferating fibrous tissue. The osteochondral junctions in the latter two specimens were irregular. We believe that the documentation of this tumor at different stages of development has helped in the further understanding of this rare entity.

Adult

Fate of the autologous tri-cusp-valved pericardial conduit in the right ventricular outflow tract of growing pigs.

No perfect valve or valved conduit is currently available to reconstruct the right ventricular outflow tract (RVOT) in pediatric patients. To investigate the fate of autologous pericardial valved conduit, twenty piglets weighing 12.2 +/- 1.4 kg were divided into two groups. In 10 of them, the pericardium was immersed in 0.6% glutaraldehyde for 5 minutes (Gr PG) and then washed with normal saline. In the other 10 pigs, the pericardium was immersed in normal saline only (Gr PN) after procurement. Afterwards the autologous pericardium was tailored as designed to build a tri-cusp-valve inside the pericardial conduit with reconstruction of the sinus of Valsalva. This conduit was connected to the pulmonary trunk (PT) distally and RVOT proximally without a pump. The PT was then doubly ligated just above the annulus. The pigs survived 114 +/- 92 days in Gr PG and 82 +/- 50 days in Gr PN. The body weight increased to 42 +/- 29 kg in Gr PG and 30 +/- 9 kg in Gr PN. No cusps adhered to the conduit wall in either group. In Gr PN, the valve became retracted; in 7 of them an aneurysm developed proximal to the stenotic pulmonary valve, while only one pig in Gr PG developed an aneurysm. In Gr PG, the leaflet and conduit showed evidence of growth. In contrast, no evidence of valve growth was found in Gr PN. Calcification was evident more in Gr PG than in Gr PN either on the leaflet (9/10 vs. 5/10) or in the wall of conduit (8/10 vs. 6/10), but the differences were not statistically significant.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals

Atypical myxoma.

We report the case of a 38-year-old woman with a large thin-walled cystic mass (6 x 5 x 4.5 cm) filled with arterial blood in the right atrium. The cystic mass with blood content was clearly delineated by transesophageal cross-sectional echocardiography and magnetic resonance imaging of the heart. At operation, a silver-whitish, smooth surfaced cystic mass was found attached to the free wall of the right atrium between the superior vena cava and the right atrial appendage with a broad base. Microscopically, the wall of the cyst was composed of stellate mesenchymal cells embedded within a myxoid matrix which was proved by alcian blue stain. To our knowledge, this type of cardiac myxoma has not been previously reported.

Adult

Primary malignant tumor of the small intestine.

The records of 101 patients with primary small intestinal malignant tumor at NTUH, collected from 1960 to 1989, were reviewed. These patients represented 1.2% of the patients with gastrointestinal cancer at NTUH over the same period. Fourty-two (41.6%) of the cancer patients had lymphomas, 30(29.7%) had adenocarcinomas, 26 (25.7%) had leiomyosarcomas, and 3(3.0%) had carcinoid tumors. The average age at cancer presentation was 47.5 years (range from 3 to 96). The lymphoma patients had an average age of 35.1 years, while adenocarcinoma patients averaged 60.4 years of age. Leiomyosarcoma and carcinoid tumors averaged 51.2 years and 59 years, respectively. There were 65 male patients and 36 female patients, and there was a male predominance in all groups except for the leiomyosarcoma group which had an equal sex ratio. Generally speaking, the incidence rate for the areas involved were similar in the duodenum, jejunum and ileum. However, adenocarcinomas were more common in the duodenum (53%) and 45% of lymphomas were found in the ileum, as were the carcinoid tumors (66%). The most common presenting symptom was abdominal pain (62%), with bleeding second (32%). Obstruction and palpable mass together were present in 29% of the cases. Body weight loss was found in 25% of patients, and 14% of the patients presented with acute abdomen due to intestinal perforation. Laparotomy was the most common diagnostic procedure (60%). Preoperative diagnoses were possible in cases of duodenal and upper intestinal malignancies, but were rarely possible in patients with lower intestinal malignancies. Sixty-eight patients (68%) underwent tumor resection for palliation or cure. The operation mortality was 4%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent

Coefficient of variation of nuclear diameters as a prognostic factor in papillary thyroid carcinoma.

To determine whether the coefficient of variation (CV) of nuclear diameters can be used as a prognostic factor in papillary thyroid carcinoma, we reviewed fine needle aspiration smears with Riu's stain from 55 operated-on and pathologically verified cases with a median follow-up of 6.5 years. For each case we measured the nuclear diameters of 100 cancer cells by ocular micrometry and calculated the CV of the nuclear diameters. Then we correlated the CV with the clinical stage, recurrence and death. There was a positive correlation between the CV of the nuclear diameters and the clinical stage (r = .59, P less than .0001). Recurrent cases (n = 10) had a higher CV than did those without recurrence (n = 45) (18.04 +/- 4.1% [mean +/- SD] versus 13.2 +/- 2.7%, P less than .0005). All recurrent cases had a CV greater than 13%. The cases in which death occurred (n = 5) had a higher CV than did those with survival (n = 50) (20.1 +/- 4.9% versus 13.5 +/- 2.7%, P less than .0005). All cases in which death occurred had a CV greater than 15%. The extent of variation of nuclear diameters was one of the factors influencing prognosis in papillary thyroid carcinoma. It offers a prognostic adjunct to standard clinical and histologic analysis.

Adult

Familial medulloblastoma in siblings: report in one family and review of the literature.

Two siblings in a family--a 5-year-old boy and an 8-year-old girl--suffered from progressive headache and gait disturbance in an interval of 1 year, consecutively. Neurologic manifestations were papilledema and truncal ataxia. Both of their computed tomography scans showed a large, well-enhanced tumor located in the cerebellar vermis with secondary hydrocephalus. Both had surgical resection followed by craniospinal irradiation and then chemotherapy. The pathologic findings confirmed the diagnosis of medulloblastomas. The family pedigree disclosed some other cancer in close relatives. These findings suggested a possible role of heredity in the oncogenesis of this tumor. To our knowledge, our cases are the seventh report of familial medulloblastoma occurring in nontwin siblings in the world.

Brain Neoplasms

[Experimental hip dysplasia in the rabbit].

Neglected cases of congenital dislocation of the hip (CDH) always present with profoundly interesting X rays and pathoanatomical changes. Because of progressive dysplastic change, it is difficult to determine clinically at what stage a patient can not have reconstructive surgery. We used an animal model to induce hip dysplasia in order to understand the mechanism of dislocation and to demonstrate the dysplastic changes at various ages of dislocation. We used a plastic tube to immobilize the left knee of one week old New Zealand white rabbits in the extension position. Fifty-five rabbits in a natural history group were examined physically, radiographically and pathologically every month, until five months old. Ten rabbits were also studied by computed tomography before sacrifice. Forty-two rabbits which had been immobilized for more than 2 months were selected to determine the changes in their left hips. Tenotomy of the hamstrings of the left knee was performed in another 20 rabbits, which were then immobilized in the same way until 2 months old. The changes in their left hips were also determined and compared with the changes of former group. In our study, immobilization of the left knee of rabbits can induce dislocation, subluxation or no change. Tenotomy of the hamstrings can decrease the incidence of dislocation and subluxation, but cannot avoid their occurrence. In long-term observation of rabbits with dislocation and subluxation, we found that there are more dysplastic and degenerative changes in older rabbits. Computed tomography proved to be an effective evaluation tool of the size of dysplastic acetabulum and femoral head.

Animals

The atrioventricular conduction axis of hearts with isolated ventricular septal defects.

We studied the surgical anatomy of 14 hearts with isolated ventricular septal defects and the precise relationship of the atrioventricular conduction axis to their rims. Ten of these hearts were investigated by serial sectioning of their atrioventricular conduction systems. All defects were divided into perimembranous or muscular types as previously suggested by Soto et al. The distinguishing feature of the perimembranous defect was that the central fibrous body formed part of its rim, this fact indicated that the conduction tissue was always to the right of the surgeon's hand when the defect was approached through the right atrium. The precise relationship of the ventricular conduction tissues varied depending upon whether the perimembranous defect extended into the inlet, trabecular or outlet components of the muscular septum. The nonbranching bundle was closest to the septal rim in the inlet and trabecular defects, frequently being buried in a remnant of the interventricular membranous septum. However, in these defects the nonbranching and branching bundles were also found in other specimens remote from the septal crest, yet were carried on the left ventricular aspect of the septum. In perimembranous inlet defects, the penetrating bundle detoured deep into the central fibrous body. In perimembranous outlet defects, the conduction tissues were remote from the septal crest. In contrast to these findings, the conduction tissues were away from the edges of the defects in trabecular and outlet muscular defects. In conclusion, in the perimembranous inlet defect, the placement of the sutures on the annulus of tricuspid valve should be avoided in view of its abnormal long penetrating bundle.

Atrioventricular Node

Correlation between sonography and pathology in thyroid diseases.

Ultrasonography was performed on the thyroid glands of 47 patients with various thyroid diseases, in a fresh state, immediately following operation. The thyroid glands were then sectioned along the plane of the most significant sonographic changes. The pathologic changes of the sectioned plane were observed and compared with the sonographic changes. In nodular goiter, the sonographic changes were usually heterogeneous. The margin was either well-defined or ill-defined, and cystic changes might play a minor or major part in the thyroid nodules. In follicular adenoma, the changes were isoechoic in adenoma with embryonal type follicles and hyperechoic in adenoma with colloid type follicles. In adenoma of the oxyphilic cells, the echogenicity was somewhat greater in the hemorrhagic part compared to the area with oncocytic change only. In papillary carcinoma, the lesions usually manifested as well-limited, heterogeneous, hypoechoic nodules. Cystic degenerations were frequently noted. There were discrete particles corresponding to microcalcification in 4 out of 6 cases. In follicular carcinoma, the sonographic changes also showed well-limited nodules. However, the echogenicity was not decreased as much as in papillary carcinoma, and it could be either homogeneous and isoechoic, or hypoechoic. Relatively large particles with an acoustic sign, which corresponded to calcification, were noted in 2 out of 4 cases. In medullary carcinoma, the lesion was well-limited and hypoechoic. The particles present in sonography corresponded to calcification in the amyloid. In Graves' disease, the main sonographic change was a diffusely homogeneous, isoechoic or hypoechoic lesion. Cystic change was rarely present. Dispersed particles were rarely present and corresponded to fibrosis in the thyroid tissue.(ABSTRACT TRUNCATED AT 250 WORDS)

Goiter, Nodular