Allium cytogenetics: a critical review on the Indian taxa

The genus Allium Linnaeus, 1753 (tribe Allieae) contains about 800 species worldwide of which almost 38 species are reported in India, including the globally important crops (onion, garlic, leek, shallot) and many wild species. A satisfactory chromosomal catalogue of Allium species is missing which has been considered in the review for the species occurring in India. The most prominent base number is x=8, with few records of x=7, 10, 11. The genome size has sufficient clues for divergence, ranging from 7.8 pg/1C to 30.0 pg/1C in diploid and 15.16 pg/1C to 41.78 pg/1C in polyploid species. Although the karyotypes are seemingly dominated by metacentrics, substantial variation in nucleolus organizing regions (NORs) is noteworthy. The chromosomal rearrangement between A.cepa Linnaeus, 1753 and its allied species has paved way to appreciate genomic evolution within Allium. The presence of a unique telomere sequence and its conservation in Allium sets this genus apart from all other Amaryllids and supports monophyletic origin. Any cytogenetic investigation regarding NOR variability, telomere sequence and genome size in the Indian species becomes the most promising field to decipher chromosome evolution against the background of species diversity and evolution, especially in the Indian subcontinent.

Shelf life and colonization of soil by clay based cyanobacterial inocula

Four heterocystous cyanobacteria, isolated from grasslands of Ujjain were selected to prepare the clay based inoculants. Inoculants were evaluated for shelf life in terms of the titer value at 6 month intervals for 24 months. For colonization by inoculants in natural grasslands, the clay based inocula were applied to the field at: 40, 80 and 120 kg/ha and their survival was estimated at different time interval. Fuller's earth based inoculants had showed 50-65% survival after two year storage. After showing an initial decline, the population of the inoculated cyanobacteria became stable after 3 months. The inoculated strains persisted in the soil for longer duration, even after four months, their population was about 10-70 times higher than that of the uninoculated plots.

Picture archiving and communication system-asynchronous transfer mode network in a midsized hospital

This article describes the pathway to full implementation of a hospital information system-picture archiving and communication system-wide area network (HIS-PACS-WAN) in a 300-bed acute care hospital, and the linking of that system to two other off-site medical centers. The PACS included direct digital capture of computed tomography (CT), magnetic resonance (MR) imaging, nuclear medicine, and ultrasonography images into an Olicon archive. Plain radiographs and fluoroscopy images were digitized manually and archived into an Olicon system. The active archive included current images on each Olicon workstation and the juke box. Long-term archiving of the images on removable optical discs, which would be loaded manually by an operator every time a request for one of these studies appeared on the operator's monitor, also was implemented. Ability to store, retrieve, and display simultaneously the physician's report of each procedure along with the images was an ultimate goal. The WAN is to be used for teleradiology and teleconferencing among the three medical centers involved in this study as well as other off-site locations. Phase I included the design and installation of the local area network (LAN) in the Department of Radiology at Olive View-UCLA Medical Center. This included the clinics and the inpatient and hospital-wide fiber-optic network and its linkage to the local telephone company. Phase II involved linkage of the Olicon workstations to imaging equipment. This implementation has been delayed significantly because of inadequate needs assessment, absence of planning for forward-compatibility to imaging equipment, and incompatibilities in DICOM conformance among vendors. Every PACS project must include an in-depth needs analysis, which should be updated yearly because of rapid turnover of technology. Although this analysis should have a heavy emphasis on clinical needs, it must incorporate the hospital-wide needs for an integrated information systems network. Integration of PACS, HIS, RIS, and a dictation/transcription system is a complex task that requires a full-time, clinically oriented project officer for successful completion.

Postcontrast MRI of cranial meninges: leptomeningitis versus pachymeningitis

OBJECTIVE

Our goal was to characterize the patterns of meningeal enhancement in postcontrast MR images and correlate these patterns with the clinical disorders.

MATERIALS AND METHODS

The MR scans, medical records, and laboratory findings of 83 patients, whose postcontrast MR studies of the head demonstrated meningeal enhancement, were reviewed retrospectively. The patterns of enhancement of the different layers of the meninges were divided into two types: leptomeningeal (pia and arachnoid), when enhancement of the meninges followed the convolutions of the gyri and/or involved the meninges around the basal cisterns; and pachymeningeal (dura), when the enhancement was thick and linear or nodular along the inner surface of the calvarium, falx, or tentorium without extension into the cortical gyri or basal cistern involvement. Enhancement around the basal cistern was considered leptomeningeal, since the dura-arachnoid is widely separated from the pia-arachnoid in this region. Further, the meningeal enhancement was divided into five etiologic subgroups, i.e., carcinomatous, infectious, inflammatory, reactive, and chemical. The medical history, clinical presentation, and findings on CSF analysis were used to distinguish infectious from carcinomatous meningitis. Meningeal enhancement due to surgery, shunt, or trauma was considered reactive, while ruptured cysts (dermoid or cysticercoid) or intrathecal chemotherapy were classified as chemical meningitis. Meningitis secondary to involvement by collagen vascular disease or sarcoidosis was considered to be inflammatory.

RESULTS

Thirty of the 83 subjects had carcinomatous, 28 infectious, 14 reactive, 8 chemical, and 3 inflammatory etiology for meningitis. Twenty-five cases (83%) of the carcinomatous, 14 (100%) of the reactive, 3 (100%) of the inflammatory, and 1 (12%) of the chemical meningitis subgroups demonstrated pachymeningeal enhancement, while 28 cases (100%) of the infectious meningitis and 7 (78%) of the chemical meningitis subgroups had leptomeningeal enhancement. Only five cases (17%) of the carcinomatous meningitis subgroup showed leptomeningeal enhancement. Four of these five cases were as a result of direct spread of intraparenchymal tumors or through perineural extension, rather than hematogenous involvement. Only one patient with carcinomatous meningitis demonstrated leptomeningeal enhancement without clear intraparenchymal lesion.

CONCLUSION

The recognition of various patterns of meningeal enhancement (leptomeningitis versus pachymeningitis) may help in differentiating between infectious and carcinomatous meningitis. This study demonstrated that infectious meningitis presents mostly as leptomeningitis, while carcinomatous meningitis presents as pachymeningitis.

Imaging of gallbladder carcinoma

Although carcinoma of the gallbladder has a low overall prevalence, it is the most common malignant tumor of the biliary tract. Retrospectively, 59 cases of histologically proved gallbladder carcinoma were reviewed. The series consisted of 42 women and 17 men, ranging in age from 35 to 86 years. Clinical manifestations of gallbladder carcinoma include right upper quadrant pain, anorexia, weight loss, and jaundice. Radiologic findings included focal or diffuse thickening of the gallbladder wall (49%), a mass in the gallbladder fossa (37%), and an intraluminal mass (14%). Associated findings were cholelithiasis (64%), biliary duct dilatation (38%), invasion of the adjacent structures (67%), distant metastases other than those of the liver (3%), and porcelain gallbladder (4%). The histologic diagnoses were adenocarcinoma (90%) and squamous cell carcinoma (10%). Differential diagnoses include all conditions in which the gallbladder wall appears thickened. A general awareness of the radiologic features of gallbladder carcinoma enhances preoperative diagnoses.

The effect of colchicine on meiosis in the Rhoeo discolor stabile complex translocation heterozygote

Rhoeo discolor (2n = 12) was used to study the effect of colchicine on chromosome pairing during meiosis. Pachytene pairing appeared unaffected, but only 17.5% of the PMCs formed a ring of 12 chromosomes at metaphase I of meiosis. While 27.5% of cells had a complete chain of 12, 49.0% had chain configurations of varying (2–11) number of chromosomes and 6.0% had complete univalence. Adjacent orientation was found in the majority of cells with chain complexes of 2–11 chromosomes. The result was highly disturbed anaphase I where 58.4% PMCs were abnormal. It is concluded that the presence of aberrant cells at metaphase I is either due to colchicine-induced ineffectiveness of pairing at the very small pairing regions or failure of chiasma formation.Key words: colchicine, meiosis, Rhoeo discolor, translocation heterozygote, univalents, alternate/adjacent orientation.

Patterns of gallium uptake in amebic liver abscesses

Imaging with Ga-67 and Tc-99m sulfur colloid was performed in ten patients with amebic liver abscesses. The most common imaging pattern appeared to be with the sharp identification of a "rim" sign on delayed Ga-67 imaging, from 48-72 hours.

Quantitative differences between the thyroid uptake of 123I and 99mTc

Unlike 123I, sodium pertechnetate Tc99m is known to be trapped by the thyroid gland without being further processed. Whether this property alone explains the total difference between the early thyroid uptake of these two isotopes was studied in a group of goitrous patients. The absolute activities of 99mTc were measured by a conjugate-view counting method and those of 123I by a coincidence counting method. The uptake was continuously registered to give uptake curves which were analyzed according to a three-compartment model of the thyroid. Both isotopes are postulated to bind to some carriers and then to be transported into the thyroid gland before they are further metabolized. Although the differences observed between the two uptakes were somewhat model dependent, the application of compartmental analysis provides a more detailed description of the differences between the two uptakes which occur even before the organification step.

In vivo evaluation in intrathyroidal iodide metabolism

A new coincidence counting method is used to measure absolute thyroid 125I activity with accurate correction of extrathyroidal neck activity. Data collected are analyzed according to a three-compartment model, giving parameters both dependent and independent of plasma iodide concentration. Iodide is postulated to form a complex with the iodide trap before it is transported and organified. The initial carrier-iodide complex, the intrathyroidal free iodide, and the thyroidal organic iodide pool can be determined as percentages of the injected activity. The trapping rate, the leakage rate, and the organification rate for iodide are determined as fractional turnover rates of the compartments independent of the plasma iodide concentration. The analysis is applied to the study of intrathyroidal iodide metabolism in a group of goitrous patients and a group of treated hyperthyroid patients. In the euthyroid goitrous patients, the trapping rate is slow, ranging from 0.051-0.085 min-1, and the intrathyroidal iodide pool is characteristically small, being 0.017-0.118%. The organification rate is 0.628-1.19 min-1. The leakage of iodide is virtually zero. In the treated hyperthyroid group, organification is not detectable, due to suppressive treatment by thionamides. The trapping rate is elevated (0.199-0.592 min-1), and the leakage rate is estimated to be in the range of 0.057-0.157 min-1. Because of the organification block, the intrathyroidal iodide pool is larger than that of our euthyroid group, being 1.50-7.59%. The compartment sizes and fractional turnover rates are in good agreement with previously reported values.

Ornithine metabolism in normal subjects and patients with cancer

The metabolism of L-(1-14C)ornithine monohydrochloride was monitored in patients with histologically proven cancer and in normal volunteers. Following i.v. injection of 8 microCi C-14 ornithine (160 nmoles), the decarboxylation of ornithine--yielding 14CO2--was monitored for a 2.5-hr period using the ionization chamber and vibrating-reed electrometer of Tolbert, as modified by Davidson and Schwabe. Twelve normal subjects exhaled 7.3-15.7% of the administered C-14 (mean 12.6% s.d. 3.11%). In ten patients tested before initiation of therapy, recovery ranged from 18.2-32.1% (mean 23.02%, s.d. 4.52%). A t-test indicates a confidence level of > 99.5% that a significant difference exists between the two means. Re-testing of two normal volunteers showed little or no change in ornithine metabolism over a 2-5-mo period. Results from testing three cancer patients before and after therapy correlate well with clinical evidence of the presence of tumor burden.

Ornithine as a possible marker of cancer

The nonprotein amino acid ornithine is the major source of polyamines in mammalian physiological systems. Increased urinary polyamine levels have been demonstrated in humans with varied types of cancers. The metabolism of DL-[1-14C]ornithine monohydrochloride in rats with either Walker 256 carcinoma or chemically induced methylcholanthrene tumors was studied. Following the i.p. injection of 3 muCi[14C]ornithine per 100 g body weight, the decarboxylation of ornithine-yielding 14CO2 was monitored by utilizing the vibrating reed electrometer-ionization chamber model of Davidson and Schwabe. Tumor-bearing animals showed significant increases in ornithine metabolism as compared to controls; for Walker 256 the tumor-bearing animal to control ratio rose from 1.16 to 1.78, for methylcholanthrene implants it rose from 1.19 to 1.82, and for methylcholanthrene paintings it rose from 1.00 to 2.20. With tumor regression ornithine levels of metabolism in the tumor-bearing animals returned to base line or nearly base-line levels. These results encourage us in our attempt to develop ornithine as a biological marker of cancer.

111Indium-bleomycin breast and axilla imaging

111Indium-Bleomycin (111In-Blm), a new radiopharmaceutical, was administered intravenously to 37 patients with benign and malignant breast lesions. Early and delayed images of both the breasts and axillae were made, and results were correlated with physical examination, histopathology of the excised lesion, mammography, and thermography. In 18 patients with malignant disease, clinical examination of the breast and axilla correlated with histopathology in 78 and 54% of the cases, respectively. Images of the breast were accurate (true positives) in 83% of the cases. Images of the axilla were accurate in 62% of the cases. Mammography was correct and suggested malignancy in 88%, and thermography in 73% of the cases. In 19 patients with benign breast lesions, clinical examination of the breast and axilla correlated with histopathology in 68 and 95% of the cases, respectively. Scans of the breast and axilla were correct (true negative) 79 and 95% of the time, respectively. Mammography was correct, and suggested benignancy, in 53% and thermography in 25% of the cases. Imaging of the breasts using 111In-Blm appears to be as accurate as physical examination and mammography for palpable benign and malignant breast tumors. It is less accurate than mammography for microscopic malignancies. Axillary imaging does not appear to be worthwhile because many axillary metastases are too small for detection with current nuclear medicine instrumentation.