Peltate trichomes in the dormant shoot apex of Metrodorea nigra,a Rutaceae species with rhythmic growth

• In Metrodorea nigra, a Rutaceae species with rhythmic growth, the shoot apex in the dormant stage is enclosed by modified stipules. The young organs are fully covered with peltate secretory trichomes, and these structures remain immersed in a hyaline exudate within a hood-shaped structure. Our study focused on the morpho-functional characterization of the peltate trichomes and cytological events associated with secretion.
• Shoot apices were collected during both dormant and active stages and processed for anatomical, cytochemical and ultrastructural studies.
• Trichomes initiate secretion early on, remain active throughout leaf development, but collapse as the leaves expand; at which time secretory cavities start differentiation in the mesophyll and secretion increases as the leaf reaches full expansion. The subcellular apparatus of the trichome head cells is consistent with hydrophilic and lipophilic secretion. Secretion involves two vesicle types: the smaller vesicles are PATAg-positive (periodic acid/thiocarbohydrazide/silver proteinate) for carbohydrates and the larger ones are PATAg-negative. In the first phase of secretory activity, the vesicles containing polysaccharides discharge their contents through exocytosis with the secretion accumulating beneath the cuticle, which detaches from the cell wall. Later, a massive discharge of lipophilic substances (lipids and terpenes/phenols) results in their accumulation between the wall and cuticle. Release of the secretions occurs throughout the cuticular microchannels.
• Continued protection of the leaves throughout shoot development is ensured by replacement of the collapsed secretory trichomes by oil-secreting cavities. Our findings provide new perspectives for understanding secretion regulation in shoot apices of woody species with rhythmic growth.

     

Aspiration cytodiagnosis of small cell malignancies found in fine needle aspirate (FNA) of the liver: an immunocytochemical study

In this study the features of small cell malignancies found in the liver by fine needle aspiration cytology (FNAC) and immunostains required for a diagnosis and differential diagnosis are presented. The material consisted of 197 fine needle aspirates which were performed under image guidance between January 1982 to October 1999. Of these, 30 were diagnosed as small cell malignancies. The age of patients ranged between 46 and 68 years. The aspirated material was examined using Papanicolaou-stained filter preparations and cell blocks, the latter stained with hematoxylin and eosin and a panel of immunoperoxidase stains. The diagnoses based on a correlation of relevant clinical history, cytohistological findings and immunostaining were: metastatic small cell anaplastic carcinoma of lung (n = 6); neuroendocrine tumour (n = 9); non-Hodgkin's lymphoma (n = 4); well-differentiated cholangiocarcinoma (n = 2); metastatic carcinoma of the prostate (n = 2); metastatic adenocarcinoma (n = 4) and metastatic carcinoma breast (n = 3). This study emphasizes the wide range of neoplasms that enter into the differential diagnosis of small cell malignancies found in the liver and a correlation of clinical, cytohistological and immunostaining findings which seem to be useful in suggesting a diagnosis.     

A review of post-trachelectomy isthmic and vaginal smear cytology

Currently in the UK cervical cancer has a peak incidence in women aged 35-39. Fertility-conserving surgical treatment by radical trachelectomy is established in the management of early disease. This study aimed at establishing the value of cytology in follow-up after trachelectomy. The cytological features of isthmic-vaginal smears post-trachelectomy for cervical cancer are presented together with a discussion of relevant clinical issues. One hundred and ninety seven smears from 32 women were reviewed. Two of the 32 patients developed pelvic recurrences. In both cases recurrence was detected cytologically long before development of a clinical or radiological abnormality. There is, however, a potential for overcall due to the presence of endometrial cells. These were present in large numbers and varying configurations in 58% of smears and led to a false positive report of malignancy in 2% of smears. The rate of referral for a cytologist opinion was significantly higher in smears containing endometrial cells (26%) than those without (13%). While all smears contained squamous cells, 41% contained squamous cells only and it is proposed that such smears should be reported as unsatisfactory in the first 2 years after surgery and negative thereafter, although the absence of glandular cells should be recorded. When an abnormality is reported, smear review and multidisciplinary discussion may avoid unnecessary investigations.     

The Diagnosis of Pneumocystis Carinii Pneumonia By Cytologic Evaluation of Papanicolaou and Leishman-Stained Bronchoalveolar Specimens In Patients With the Acquired Immunodeficiency Syndrome

The presence of foamy alveolar casts or flocculent material in Papanicolaou and Leishman-stained smears of bronchoalveolar lavage (BAL) fluid is said to be indicative of infection with Pneumocystis carinii. We have investigated the sensitivity and specificity of this method of diagnosing pneumocystis pneumonia in patients with the acquired immunodeficiency syndrome (AIDS). Patients (n= 114) with diffuse lung infiltrates were submitted to fibreoptic broncoscopy and BAL. Seventy of them were patients with AIDS. the other 44 individuals were not infected by the human immunodeficiency virus (HIV). Pneumocystis carinii organisms were identified on Grocott's methenamine silver (GMS)-stained BAL smears in 30 patients with AIDS. Flocculent material was present in the Papanicolaou and Leishman-stained smears from all of these cases. Conversely, P. carinii were not seen on GMS-stained smears in the remaining 84 individuals with or without AIDS. No flocculent material was observed in Papanicolaou or Leishman-stained smears in these 84 patients. We concluded that the presence of flocculent material in Papanicolaou or Leishman-stained smears of BAL fluid is indicative of P. carinii pneumonia in patients with AIDS. La présence de cylindres alvéolaires spumeux ou de matériel floculé dans les étalements de liquide de lavage bronchoalvéolaire (LBA) colorés selon Papanicolaou ou Leishman est considérée comme symptomatique d'une infection par Pneumocystis carinii. Nous avons étudié la sensibilité et la spécificité de cette méthode de diagnostic de l'infection par Pneumocystis carinii chez des patients atteints de syndrome de déficience immunitaire acquise (SIDA). Cent quatorze malades avec des infiltrats pulmonaires diffus ont subi une fibroscopie bronchique et un lavage broncho-alvéolaire. Soixante dix d'entre eux edtaient atteints de SIDA, 44 n'étaient pas infectés par le Virus de l'Immunodéficience Humaine (VIH). Le Pneumocystis carinii a été identifiié par la coloration de Grocott chez 30 patients atteints de SIDA. Chez ces patients, la présence d'un matériel floculé est constante sur les étalements colorés au Papanicolaou et au Leishman. A l'inverse, Pneumocystis carinii n'a pas été retrouvé chez les 84 autres malades, atteints ou non du SIDA et les étalements de LBA ne contenaient pas de matériel floculé. En conclusion, la présence de matériel floculé dans les étalements de LBA colorés selon Papanicolaou ou Leishmanest associée à une pneumpathie àPneumocystis carinii chez les patients atteints de SIDA. Sensitivität und Spezifität des Nachweises schaumiger oder flockiger Alveolarausgüsse bei Pneumocystis carinii wurden in 114 Fällen diffuser Lungeninfiltrate untersucht. 70 Patienten waren an AIDS erkrankt, 44 weitere waren HIV-negative. In 30 der AIDS-Fälle wurde P. carinii mit der Grocott'schen Färbung nachgewiesen. Die typischen Eiweißniederschläge waren in all diesen Fällen nachweisbar. Umgekehrt ergab die Grocottfärbung in 84 Fällen mit oder ohne AIDS ein negatives Ergebnis. In all diesen Fällen war kein Eiweißniederschlag nachweisbar. Daraus ergibt sich, daß die Eiweißniederschläge in Präparaten, die nach Papanicolaou oder Leishman gefärbt wurden, kennziechned sind für die P. carinii Pneumonie.     

Carcinoma in situ of the cervix and its malignant potential. A lesson from New Zealand

An overview of studies attempting to define the natural history of carcinoma in situ of the cervix suggests that 20-30% of lesions progress to invasive carcinoma within 5-10 years. This risk of invasion and the inability to predict when invasion might occur has been reinforced by a judicial enquiry in New Zealand so that protocols that include withholding treatment are no longer justifiable. Once a diagnosis of cervical carcinoma in situ is established appropriate treatment is mandatory.     

Lotus corniculatus L.: Morphological and cytological analysis of regenerants from three sources of tissue and selected progeny

Regenerants from three types of tissue, leaf explants (132 plants), leaf protoplasts (68 plants) and cotyledonary protoplasts (119 plants) of L. corniculatus cv Leo differed both morphologically and cytologically from control plants grown from seed. Four categories of chromosome number were found. The frequency and type of variation found in the chromosome numbers of regenerants reflected the method of plant regeneration.Regenerants with both normal and abnormal numbers of chromosomes produced progeny which were cytologically normal and showed only minor morphological changes when compared with control plants.     

Image analysis of low magnification images of fine needle aspirates of the breast produces useful discrimination between benign and malignant cases

Image analysis of low magnification images of fine needle aspirates of the breast produces useful discrimination between benign and malignant cases
Fine needle aspirates of the breast (FNAB) ( n =362; 204 malignant, 158 benign), prepared by cytocentrifuge methods and stained by the Papanicolaou technique, were analysed using a semi‐automated image analysis system at a low magnification which precluded resolution of nuclear detail. The measured parameters were integrated optical density, fractal textural dimension, number of cellular objects (single cells and contiguous groups of cells), distance between cellular objects (mean, s.d., skewness and kurtosis), area of cellular objects (mean, s.d., skewness, kurtosis) and the nearest neighbour statistic. The cases were divided into a 200‐case training set and a 162‐case test set. Analysis was performed by logistic regression and the multi‐layer Perceptron type of artificial neural network. Logistic regression and the neural network produced similar performances with a sensitivity of 82–83%, specificity 85% and a positive predictive value for a malignant result of 85%. A non‐parametric analysis of all the predictor variables showed that all except the mean area of cellular objects and the s.d. of this measurement were significant discriminants ( P <0.05), but most were highly interrelated and this was reflected in the selection of only three predictor variables by forward and backward conditional logistic regression. This study shows that much diagnostic information is present in low power views of FNAB, and that image analysis could form the basis of a semi‐automated decision‐support aid.     

Fine needle aspiration cytology of mucoepidermoid carcinoma of the thymus

Primary mucoepidermoid carcinoma of the thymus developing in an 80-year-old Japanese man is described. This is the third case report of this rare tumour which was diagnosed following fine needle aspiration cytology (FNAC) of a metastatic lesion in the left humerus. FNA showed the typical cytological findings of mucoepidermoid carcinoma, that is the presence of squamous, glandular and intermediate neoplastic cells. Histology at autopsy confirmed these findings.     

The Evaluation and Interpretation of Cervical Cytology: Application of the Likelihood Ratio Concept

The Papanicolaou smear (Pap test), used for the detection and prevention of neoplastic lesions of the cervix, is known to have both false negative and false positive results. Proper handling of the diagnostic uncertainty resulting from these errors demands quantification of flaws. Traditionally, sensitivity, specificity and predictive values are used for that aim. In this study another approach is advocated, namely the use of the likelihood ratio. For cervical cytology this ratio is the quotient of the probability of a Pap class within the diseased population to the probability of that same Pap class within the non-diseased group. This approach enables the characterization of each Pap class separately, and is therefore much better for clinical interpretation of the result. It is also a superior approach for quality assessment.