Construction and performance of a dilution-refrigerator based spectroscopic-imaging scanning tunneling microscope.

We report on the set-up and performance of a dilution-refrigerator based spectroscopic imaging scanning tunneling microscope. It operates at temperatures below 10 mK and in magnetic fields up to 14T. The system allows for sample transfer and in situ cleavage. We present first-results demonstrating atomic resolution and the multi-gap structure of the superconducting gap of NbSe(2) at base temperature. To determine the energy resolution of our system we have measured a normal metal/vacuum/superconductor tunneling junction consisting of an aluminum tip on a gold sample. Our system allows for continuous measurements at base temperature on time scales of up to ≈170 h.

A stiff scanning tunneling microscopy head for measurement at low temperatures and in high magnetic fields.

We have developed a measurement head for scanning tunneling microscopy (STM) and specifically for spectroscopic imaging STM which is optimized for high mechanical stiffness and good thermal conductivity by choice of material. The main components of the microscope head are made of sapphire. Sapphire has been chosen from several competing possibilities based on finite element modeling of the fundamental vibrational modes of the body. We demonstrate operation of the STM head in topographic imaging and tunneling spectroscopy at temperatures down to below 2 K.

Intra-operative measurement of tumour size in breast cancer and its comparison with other methods: a prospective study.

UNLABELLED: Accurate measurement of breast tumour size determines staging and prognosis. Discrepancies amongst clinical examination (CE), ultrasonography (USG), mammography, pathological examination (PE) and magnetic resonance imaging have been reported. However, few studies have evaluated changes in breast tumour size from the operating table to the laboratory. OBJECTIVES AND METHODS: A prospective study was designed to assess the intra-operative (IO) tumour size in 29 patients of breast cancer presenting to a tertiary care centre in Delhi and to compare it with CE, USG and PE. OBSERVATIONS AND RESULTS: Twenty-nine patients (mean age: 47 years), presenting with invasive duct carcinoma (stage IIIA: 31%, stage IIB: 28%), were included in the study. Comparison with mean IO (4.2 cm) revealed that both USG and PE underestimated tumour size by a mean of 0.35 cm (8.4%) and 0.45 cm (10.7%), respectively, in most patients. CE tended to overestimate size by 0.82 cm (19.8%). All three modalities showed statistically significant correlation with IO (maximum Pearson's correlation coefficient for PE=0.937, p<0.001; R(2)=0.877, maximum for PE). Two-way analysis of variance revealed mean difference in size to be statistically significant (p=0.000) only between CE and IO. DISCUSSION: Formalin processing causes changes in tumour dimensions in the breast, causing reduction in tumour size. It may also have a bearing on the assessment of surgical margins in breast conservation surgery. Immediate post-operative measurement of the specimen is ideal. Protocols for specimen fixation should be standardized.

Massive amebic liver abscess--an unusual presentation.

A 40-year-old woman presented with a huge lump in the right half of the abdomen and irregular menses. Ultrasonography showed a cystic lump with septations, extending from the upper abdomen to the pelvis; the right ovary was not seen. On exploration, there was a large cyst arising from the right lobe of the liver; the aspirate was bilious. Since the cyst wall was adherent to retroperitoneal structures, complete excision was not possible. A roux-en-Y loop of jejunum was anastomosed to the cyst wall. Biopsy of the wall showed inflammatory granulation tissue with trophozoites of Entamoeba histolytica. She was treated with metronidazole, and recovered uneventfully.

Lymphatic filariasis of the ovary and mesosalpinx.

We report 2 cases of filariasis, one in the ovary and the other in the mesosalpinx. In the first case, the patient underwent panhystrectomy and in the second case, right ovarian cystectomy with right salpingectomy were performed under general anaesthesia. Histopathology showed adult filarial worms in the dilated lymphatics of the right ovary, in the first case and in the mesosalpinx, in the second case. Both patients presented with complaints related to gynecological problems and not filariasis. Reports of filariasis in the literature and possible treatments and prevention strategies are also discussed.

Cytomorphological features, AgNOR counts and c-erb B-2 in carcinoma breast.

The present study was designed to evaluate the cytomorphological features (nuclear grade and smear pattern) and AgNOR counts in 60 cases of carcinoma breast. The smears were stained with May Gruenwald Giemsa (MGG) and Papanicolaou stains. Silver staining nucleolar organiser region (AgNOR) counts and c-erb B-2 immunostaining were also done in each case. The smear pattern was assessed and classified as 'typical', 'cluster predominant' or 'individual cell type', and the nuclei were graded as grade I, II or III. Smear pattern and nuclear grade were found to be related variables. A significant association was found between nuclear grade and AgNOR counts (p = 0.03). Also postmenopausal women had statistically significant higher nuclear grades and less cohesive cell clusters as compared to premenopausal women. Twenty-three carcinoma breast were positive for c-erb B-2, of these 14 were postmenopausal women.

Cytomorphologic patterns in Calmette Guerin bacillus lymphadenitis.

OBJECTIVE: To study the cytomorphologic patterns of Calmette Guerin bacillus (BCG) lymphadenitis and compare it to those of tuberculous lymphadenitis. STUDY DESIGN: A retrospective cytomorphologic study of 136 cases of clinically diagnosed BCG adenitis. All fine needle aspiration smears of lymphadenitis in the age group 2 months to 2 years during a three-and-half-year period were analyzed. RESULTS: Three distinct cytomorphologic patterns were seen in 112 cases. They were acid-fast bacilli in a necrotic background (62), granulomas with necrosis (47) and granulomas in a reactive lymphoid background (3). CONCLUSION: The cytomorphologic patterns in BCG lymphadenitis were similar to those seen in tuberculous lymphadenitis; however, an exudative response and high acid-fast bacillus positivity was seen more frequently in BCG lymphadenitis. Moreover, Ziehl-Neelsen staining helped to distinguish these cases from pyogenic abscesses.

Cytology. A valuable tool in prognostication of carcinoma breast.

Sixty consecutive cases of carcinoma breast diagnosed on fine needle aspiration cytology (FNAC) between July 1993 to June 1994 were studied prospectively. Nuclear grading was done on all cytologic smears, histologic grading was possible in only 22 cases. A good correlation was seen between nuclear grading on cytology and histology. Silver staining for nucleolar organizer region, and immunocytochemical staining for Ki-67 and C-erbB-2 could be done with ease on cytologic smears, providing necessary additional information on which to base the theraputic decisions.

C-erb B2 oncoprotein expression. Correlation with the Ki-67 labeling index and AgNOR counts in breast carcinoma on fine needle aspiration cytology.

OBJECTIVE: To evaluate the expression of C-erb B2 on-coprotein and study its correlation with the Ki-67 labeling index and silver-stained nucleolar organizer region (AgNOR) counts on fine needle aspiration cytology (FNAC) of breast carcinoma. STUDY DESIGN: In a prospective study, FNAC was done on 60 cases of infiltrating ductal carcinoma of the breast. Smears from aspirates were either air dried and methanol fixed for May-Grüwald-Giemsa and silver staining for AgNORs or wet fixed for Papanicolaou and immunocytochemical staining for Ki-67 and C-erb B2. RESULTS: Breast carcinoma showing overexpression of C-erb B2 had higher Ki-67 labeling indexes (mean, 21.43) and higher AgNOR counts (mean, 37.92). A statistically significant correlation (r = .8) was seen between AgNOR counts and the Ki-67 labeling index. CONCLUSION: FNAC proved suitable for studying C-erb B2 oncoprotein expression and the Ki-67 labeling index by immunocytochemistry. These parameters supplement the cytologic diagnosis.

Cytomorphology of some uncommon tumors of childhood and adolescence.

With the advent of newer adjuvant chemotherapeutic regimes resulting in dramatic improvement in survival, it is mandatory to obtain quick correct diagnosis, which is provided by fine needle aspiration cytology (FNAC). Cytology of childhood tumors was studied to find any distinguishing features, which would help in arriving at a diagnosis. Cytomorphology of 386 childhood and adolescent (0-19 years) tumors diagnosed between 1984 and 1993 were studied. Lipoma was the commonest benign tumor in 0-14 years age group. Fibroadenoma of the breast was the common benign tumor in adolescent (10-19 yrs) girls and pleomorphic adenoma in adolescent (15-19 yrs) boys. Wilms' tumor was the most frequent solid malignant tumor in preschool children and Hodgkin lymphoma, mixed cellularity in the school going age (5-19 yrs). Malignant tumors were more frequent (199). In addition, some rare malignancies like hepatoblastoma, meningioma, ganglioneuroblastoma, adrenocortical carcinoma, clear cell sarcoma kidney and malignant histiocytosis were diagnosed. The cytological features and the differential diagnoses are discussed. It is possible to diagnose these uncommon tumors if particular attention is paid to the distinguishing cytomorphological features in correlation with clinicoradiological findings and cytochemistry.

Absence of human papillomavirus DNA in breast cancer as revealed by polymerase chain reaction.

Oncogenic human papillomavirus (HPV) types 16 and 18 commonly associated with cervical cancer are found in many epithelial malignancies at extra-genital sites including breast. The transforming gene products of HPV have also been shown to immortalize breast epithelial cells in vitro. But the findings of HPV DNA in breast carcinoma are found to be contradictory. In the present study fine needle aspirate cell (FNAC) samples from 26 breast cancer patients and four breast tumour biopsies were analysed for the presence of HPV 16 and 18 DNA sequences by both polymerase chain reaction (PCR) and Southern blot hybridization. Of 26 fine needle aspirate cell samples and four breast cancer biopsies, not a single sample was found to be positive by either PCR or Southern blot hybridization. The observation of complete absence of HPV DNA sequences in breast cancer refute the possibility of any role for oncogenic genital HPV types 16 and 18 in the pathogenesis of breast cancer.

Immunoreactivity with S100 protein as an indicator of pregnancy.

The usefulness as a pregnancy marker, of immunoreactivity with S100 protein antiserum in endometrial curettings and fallopian tubes during pregnancy was assessed. Twenty six placental tissues of various gestational age, two hydatidiform moles and four fallopian tubes removed for ectopic pregnancy were stained with S100 protein polyclonal antiserum by immunoperoxidase technique. Strong immunostaining was found in glands within the decidua and epithelial cells of fallopian tubes during early pregnancy. However, no S100 protein could be demonstrated in the endometrium in various phases, endometrial carcinomas, decidual glands beyond 12 wk of gestation and normal fallopian tubes. The results indicate a relationship between S100 protein and early pregnancy. Positive immunoreactivity with S100 protein antiserum in the decidual glands and fallopian tube epithelium may help in confirmation of doubtful cases of pregnancy.

Cytologic diagnosis of tuberculous lymphadenitis in children by fine needle aspiration.

One hundred consecutively diagnosed cases of tuberculous lymphadenitis in children have been analysed retrospectively. All cases were stained by May Grunwald Giemsa for cytomorphology and Ziehl Neelsen stain for acidfast bacilli (AFB). In 52 cases the material was sufficient and AFB cultures were possible. A diagnosis of tuberculosis was made when smears showed epithelioid cell granulomas or AFB on either smears or culture. M. tuberculosis and atypical mucobacteria were cultured in 26 and 3 cases respectively. In 6 cases the diagnosis of tuberculosis would have been missed but for culture studies, the cytologic smears were necrotic and stains for AFB negative.

Histopathological study of xanthogranulomatous cholecystitis.

A total of 418 gallbladders removed surgically as chronic cholecystitis or carcinoma gallbladder were studied retrospectively for the presence of xanthogranulomas which were found in 45 (10.8%). The age of patients with xanthogranulomatous cholecystitis ranged from 15 to 80 yr with a mean of 45.3 indicating an early presentation of the disease in our population. The male to female ratio was 1:8. The gallbladder was invariably thickened and calculi of cholesterol or mixed type were present in all cases. Xanthogranulomatous foci appeared as yellowish nodules 2-15 mm in size, on the mucosal surface. In some gallbladders, the involvement was diffuse and these foci extended to the surrounding structures. Histologically, xanthogranulomas encompassed the full thickness of the gallbladder wall with variable extension into adjacent fat and connective tissue. This entity deserves distinct clinicopathological recognition, particularly because of a possible confusion with malignancy and the associated complications.