Fertility preservation in female oncology patients: the influence of the type of cancer on ovarian stimulation response

STUDY QUESTION

Does the type of cancer influence on the ovarian response to stimulation for fertility preservation (FP) in female oncology patients?

SUMMARY ANSWER

Patients with gynaecological cancer have less number of retrieved mature oocytes compared with haematological and breast cancer patients.

WHAT IS KNOWN ALREADY

Concerns about the impact of cancer therapy on future fertility have been raised and FP has become an important component in cancer management. Previous studies analysing FP results in cancer patients have shown conflicting findings.

STUDY DESIGN, SIZE, DURATION

This was a retrospective analytical study performed in the Centre for Reproductive Medicine, at St Bartholomew's Hospital, between January 2000 and December 2014. The aim of this study was to analyse the response to ovarian stimulation in cancer patients before undergoing cancer treatment and to determine whether any difference can be attributed to underlying cancer diagnosis. We also report the pregnancy outcomes.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A total of 531 female patients recently diagnosed with cancer were referred for counselling on FP. A total of 306 patients underwent ovarian stimulation for oocyte or embryo cryopreservation. We compared the baseline characteristics and ovarian response in five main subgroups: breast cancer, haematological cancer, gynaecological cancer, gastrointestinal cancer and others. The primary outcome was the total number of mature oocytes retrieved and pregnancy outcomes.

MAIN RESULTS AND THE ROLE OF CHANCE

The main cancer diagnosis was breast cancer with 145 patients (47.4%); 79 patients (25.8%) had haematological malignancies; 42 (13.7%) had gynaecological malignancies; 20 (6.5%) had gastrointestinal cancer and 20 (6.5%) had other types of cancer. Patients with breast cancer were older (P < 0.001). Patients with haematological malignancies had higher number of mature oocytes retrieved (P = 0.003). The number of mature oocytes retrieved was lower in patients with gynaecological malignancy compared with haematological and breast cancer patients (P = 0.005 and P = 0.045, respectively). The fertilization rate and the number of cycles cancelled were comparable between all the groups. Thirty-two embryo transfer cycles have been done in 22 patients who have returned to attempt pregnancy. Pregnancy rate per transfer cycle was 43.75%, and cumulative pregnancy rate per patient was 54.5%. Live birth rate per patient was 22.72%.

LIMITATIONS, REASONS FOR CAUTION

Apart from the retrospective nature of the study, patients were included over the period of 15 years, and over that time technology has changed and protocols have evolved. The results obtained from subcategory analyses should be interpreted with caution, as in each subgroup there are different types of malignancies with different number of patients in different age groups. Different ovarian stimulation protocols were applied. Only a few patients have come back to attempt pregnancy after being cured from their disease. We do not have follow-up data on these patients; as a result, we are not able to report the survival rate and the reason for non-return for embryo transfer. In addition, we cannot report information on spontaneous conceptions and births. Slow freezing used for embryo cryopreservation, high miscarriage rate and low live birth rate per transfer are other limitations of this study.

WIDER IMPLICATIONS OF THE FINDINGS

The current study is the largest series analysing each group of cancer separately and showing pregnancy outcomes in oncology patients undergoing FP. These results provide valuable information about the success of this technique in oncology patients.

STUDY FUNDING/COMPETING INTEREST(S)

The authors have not received any funding to support this study. There are no conflicts of interest to declare.

Developmental Expression of Claudins in the Mammary Gland

Claudins are a large family of membrane proteins whose classic function is to regulate the permeability of tight junctions in epithelia. They are tetraspanins, with four alpha-helices crossing the membrane, two extracellular loops, a short cytoplasmic N-terminus and a longer and more variable C-terminus. The extracellular ends of the helices are known to undergo side-to-side (cis) interactions that allow the formation of claudin polymers in the plane of the membrane. The extracellular loops also engage in head-to-head (trans) interactions thought to mediate the formation of tight junctions. However, claudins are also present in intracellular structures, thought to be vesicles, with less well-characterized functions. Here, we briefly review our current understanding of claudin structure and function followed by an examination of changes in claudin mRNA and protein expression and localization through mammary gland development. Claudins-1, 3, 4, 7, and 8 are the five most prominent members of the claudin family in the mouse mammary gland, with varied abundance and intracellular localization during the different stages of post-pubertal development. Claudin-1 is clearly localized to tight junctions in mammary ducts in non-pregnant non-lactating animals. Cytoplasmic puncta that stain for claudin-7 are present throughout development. During pregnancy claudin-3 is localized both to the tight junction and basolaterally while claudin-4 is found only in sparse puncta. In the lactating mouse both claudin-3 and claudin-8 are localized at the tight junction where they may be important in forming the paracellular barrier. At involution and under challenge by lipopolysaccharide claudins -1, -3, and -4 are significantly upregulated. Claudin-3 is still colocalized with tight junction molecules but is also distributed through the cytoplasm as is claudin-4. These largely descriptive data provide the essential framework for future mechanistic studies of the function and regulation of mammary epithelial cell claudins.

Correction: Photophysical properties of the intramolecular excited charge-transfer states of π-expanded styryl phenanthrimidazoles – effect of solvent polarity

Correction for ‘Photophysical properties of the intramolecular excited charge-transfer states of π-expanded styryl phenanthrimidazoles – effect of solvent polarity’ by V. Thanikachalam et al., RSC Adv., 2014, 4, 6790–6806.

Phenanthrimidazole as a fluorescent sensor with logic gate operations

A novel sensor namely, 1-(1-(p-tolyl)-1H-phenanthro[9,10-d]imidazol-2-yl)naphthalen-2-ol was synthesised for the detection of anion as well as cation through intramolecular charge transfer mechanism. This compound was used for the selective detection of Zn(2+) ion as compared to other metal ions and the binding was evidenced from the new absorption band at 356 nm and switch on fluorescence at 453 nm. The switch on fluorescence can be explained on the basis of photoinduced electron transfer (PET) mechanism and it was demonstrated by logic gate functions.

Donor-acceptor binding interaction of 1-(naphthalene-1-yl)-2,4,5-triphenyl-1H-imidazole with semiconductor nanomaterials

The dynamics of photoinduced electron injection from 1-(naphthalene-1-yl)-2,4,5-triphenyl-1H-imidazole (NTI) to pristine ZnO, Mn-doped TiO2 and BaTiO3 nanoparticles have been studied by absorption, fluorescence and lifetime spectroscopic methods. Both the absorption and fluorescence results suggest the association between the nanoparticles and NTI. The calculated free energy change (ΔGet) confirms the electron injection from NTI to nano semiconductors. The critical energy transfer distance between NTI and the nanoparticles have been deduced. The emission of NTI is enhanced by pristine ZnO and quenched by Mn-doped TiO2 and BaTiO3 nanoparticles which are likely due to change of LUMO and HOMO levels of NTI on its association with nano semiconductors. The strong adsorption of the NTI on the surface of ZnO nanocrystals is likely due to the chemical affinity of the nitrogen atom of the NTI to the zinc ion on the surface of nanocrystals. Electron injection from photoexcited NTI to the CB(S(∗)→S(+)+eCB(-)) is likely to be the reason for the fluorescence enhancement.

Binding interaction between 2-(naphthalen-1-yl)-1-p-tolyl-1H-phenanthro[9,10-d]imidazole and semiconductor nanomaterials

The binding interaction of bioactive phenanthrimidazole with nanoparticulate WO3, Fe2O3, Fe3O4, CuO, ZrO2 and Al2O3 has been studied by electronic and life time spectral studies. The phenanthrimidazole adsorbs strongly on the surface of nanosemiconductor, the apparent binding constants have been determined from the fluorescence quenching. In the case of nanocrystalline insulator, fluorescence quenching through electron transfer from the excited state of the phenanthrimidazole to alumina is not possible, but it is due to energy transfer process.

Enhancing the photoluminescence of 1-(naphthalene-1-yl)-2,4,5-triphenyl-1H-imidazole anchored to superparamagnetic nanoparticles

Synthesis and characterization of 1-(naphthalene-1-yl)-2,4,5-triphenyl-1H-imidazole has been carried out by spectral studies. The synthesized phosphated imidazole and phosphated imidazole bound magnetic nanoparticles were characterized using fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and powder X-ray diffraction (XRD). The photophysical characteristics of the synthesized phosphated imidazole and phosphated imidazole bound magnetic nanoparticles were investigated by steady-state absorption and emission spectra as well as time resolved fluorometry. The intensities of absorption and emission maxima increase in the following order, phosphated imidazole bound Fe2O3>phosphated imidazole>imidazole.

Multiple linear regression solvatochromic analysis of donar-acceptor imidazole derivatives

Catalytic synthesis of some polysubstituted imidazoles under solvent-free condition is reported and their characterization has been carried out spectral techniques. Electronic spectral studies reveal that their solvatochromic behavior depends both the polarity of the medium and hydrogen bonding properties of the solvents. Specific hydrogen bonding interaction in polar solvents modulated the order of the two close lying lowest singlet states. The solvent effect on absorption and emission spectral results has been analyzed by multiple parametric regression analysis. Solvatochromic effects on the emission spectral position indicate the charge transfer (CT) character of the emitting singlet states both in a polar and a non polar environment. The fluorescence decays for the imidazoles fit satisfactorily to a bi exponential kinetics. These observations are in consistent with quantum chemical calculations.

Kamlet-Taft and Catalán solvatochromism of some π-expanded phenanthrimidazole derivatives - DFT analysis

Some π-expanded phenanthrimidazole derivatives have been synthesised and characterised by different spectral techniques. Kamlet-Taft and Catalán solvatochromism of synthesised phenanthrimidazole derivatives have been analysed. Non-linear optical (NLO) and natural bond orbital (NBO) analysis have been made by ab initio method to show intramolecular interactions. The energies of the HOMO and LUMO levels, the molecular electrostatic potential (MEP) energy surface, NBO studies have exploited the existence of intramolecular charge transfer (ICT) within the molecule.

Radiative and nonradioactive electron transfer in donor-acceptor phenanthrimidazoles

Photoinduced electron transfer in a series of naphthyl substituted phenanthrimidazoles has been studied in solutions. The intramolecular charge transfer (CT) leads to a large Stokes shift and large dipole moment in the fluorescent state. Solvatochromic effects on the spectral position and profile of the stationary fluorescence spectra clearly indicate the CT character of the emitting singlet states of all the compounds studied. An analysis of the CT fluorescence lead to the quantities relevant for the electron transfer in the Marcus inverted region.

Sensitive and selective PET-based π-expanded phenanthrimidazole luminophore for Zn2+ ion

The novel photoinduced electron transfer (PET) chemosensor, 1-(1-(4-methoxyphenyl)-1H-phenanthro[9,10-d]imidazol-2-yl)naphthalen-2-ol [MPPN] and its zinc complex were synthesised and characterized by electronic spectral and Frontier molecular orbital energy analysis. MPPN becomes efficient fluorescent chemosensor upon binding with metal ions and shows a strong preference toward Zn(2+) ion. Density Functional theory (DFT) calculations reveal that luminescence of free MPPN originates from its orbital structure in which two π-orbitals (HOMO and HOMO-1) of the imidazole ring are situated between two π-orbitals (HOMO-2 and LUMO) of the naphthyl fragment. Therefore the absorption and emission processes occur between the two π- orbitals (HOMO-2 and LUMO). The two higher energy imidazole orbitals (HOMO and HOMO-1) serve as quenchers for the excited state of the molecule through nonradiative processes. Upon binding with Zn(2+) ion, MPPN becomes a highly luminescent with λemi - 421 nm. The significant enhancement of luminescence upon binding with Zn(2+) ion is attributed to the stabilization of HOMO-2 and HOMO-1 π-orbitals of imidazole ring upon their engagement in new bonds with Zn(2+) ion. The affinity of MPPN to zinc ion is found to be very high [K = 6 × 10(6) M(-1)] when compared with other metals ions. The nonlinear absorption coefficient γ for MPPN is 1.9 × 10(-12) m/W and 3.9 × 10(-11) m/W for MPPN-Zn complex.

Nano rutile TiO2 catalysed synthesis of (E)-4-(2-(1-(4-chlorophenyl)-1H-phenanthro[9,10-d]imidazol-2-yl)vinyl)-N,N-dimethylaniline and its interaction with super paramagnetic nanoparticles

The synthesis of (E)-4-(2-(1-(4-chlorophenyl)-1H-phenanthro[9,10-d]imidazol-2-yl)vinyl)-N,N-dimethylaniline (CPPIVI) has been carried out using TiO₂ (R) as catalyst under solvent free conditions and characterized by NMR spectral studies.

Intramolecular excited proton transfer of 1-(1-phenyl-1H-phenanthro[9,10-d]imidazol-2-yl)naphthalen-2-ol--a combined experimental and quantum chemical studies

Synthesis of the 1-(1-phenyl-1H-phenanthro[9,10-d]imidazol-2-yl)naphthalen-2-ol [PPIN] is reported, spectral and fluorescent properties of the title compound are investigated. The feasibility of excited state intramolecular proton transfer (ESIPT) has been argued from the changeover of relative stability of the enol and the keto forms on photoexcitation from the S0-PES to the S1-PES. Critical evaluation on the modulations of geometrical parameters other than the proton transfer reaction coordinate has also been undertaken. The intramolecular hydrogen bonding (IMHB) interaction in PPIN has been explored by calculation of the hyperconjugative charge transfer interaction from the lone electron pair of ring nitrogen atom to the σ(∗) orbital of O-H bond, under the provision of Natural Bond Orbital (NBO) analysis. However, DFT calculations together with the experimental results reveal that the excited species with the intramolecular N⋯HO hydrogen bond type undergoes rapid radiationless deactivation. This leads to a conclusion that the low-intensity dual-band fluorescence of the title compound in solution originates from the traces of the conformation with the -OH bond to azomethine nitrogen atom (ESIPT).

Health seeking behavior among Malaysians with acute diarrheal disease

About 1.8 million people die annually from acute diarrheal disease globally. A nationwide cross-sectional survey was conducted via face-to-face interview with eligible subjects to determine the incidence and health seeking behavior of Malaysians with acute diarrheal disease (ADD). An acute diarrheal episode was defined as having three or more loose stools in any 24 hour period during the four weeks period prior to the interview. The exclusion criteria included pre-existing chronic diarrhea, such as with cancer of the bowel, ulcerative colitis or Chrohn's disease. Forty three point three percent of those with ADD (95% CI 41.3-45.4) sought treatment for the illness. Younger age groups (0-4 years, 67.7%; 95% CI 61.5-73.4; 5-9 years, 56.5%; 95% CI 48.6-64.1) were more likely to seek care for ADD. Seventy-one point eight percent of those seeking treatment, (95% CI 69.0-74.4) did so within 12 hours of the onset of symptoms. Most people with ADD sought treatment at private clinics. The main reasons given for not seeking treatment were the illness was mild and did not warrant treatment and the practice of self-medication (22.4%; 95% CI 20.0-24.9). These findings show self-medication is a major health seeking behavior among Malaysians with ADD. Self-medication of ADD deserves more in-depth study to ensure it is safe.

Evaluation of mosquitocidal activity of Annona squamosa leaves against filarial vector mosquito, Culex quinquefasciatus Say

Methanolic extract of leaves of A. squamosa was tested for mosquitocidal effect against C. quinquefasciatus. A liquid mosquito insecticide formulation was prepared with the extract (1, 3 and 5 %w/w) using deodorized kerosene as solvent and investigated for its knock-down and 24 hr mortality. The extract formulation produced dose dependent activity, exhibited significantly shorter knock down KD50 and KD90 values and produced significant mortality. The results suggest the potential mosquitocidal effect of A. squamosa on C. quinquefasciatus.

HIV-1 viral protein R compromises cellular immune function in vivo

HIV-1 viral protein R (Vpr) is a virion-associated gene product that profoundly affects T cell proliferation, induces apoptosis and can affect cytokine production in part through interfering with NF-kappa B-mediated transcription from host cells. Collectively, these effects support that Vpr could influence immune activation in vivo. However, this effect of Vpr has not been explored previously. Here we examined the effect of Vpr expression in an in vivo model system on the induction of antigen-specific immune responses using a DNA vaccine model. Vpr co-vaccination significantly altered the immune response to co-delivered antigen. Specifically, in the presence of Vpr, inflammation was markedly reduced compared to antigen alone. Vpr reduced antigen-specific CD8-mediated cytotoxic T lymphocyte activity and suppressed T(h)1 immune responses in vivo as evidenced by lower levels of IFN-gamma. In the presence of Vpr, there is a profound shift in isotype towards a T(h)2 response as determined by the IgG2a:IgG1 ratio. The data support that Vpr compromises antigen-specific immune responses and ultimately effector cell function, thus confirming a strong selective advantage to the virus at the expense of the host.

Nocardia asteroides pericarditis in association with HIV

This case report describes Nocardia pericarditis in a newly diagnosed human immunodeficiency virus (HIV) patient as an initial manifestation. Previously, two cases of Nocardia pericarditis were reported in patients with established HIV infection. To our knowledge this is the first case of Nocardia pericarditis as an initial manifestation of HIV infection. This case substantiates and emphasizes the importance of identifying Nocardia as an infectious cause of pericarditis in patients with acquired immunodeficiency. Long-term survival may be achieved with a combined medical and surgical approach.

Animal model for liver dysfunction using lomustine in Wistar rats

AIM

To induce intrahepatic cholestasis in rats using lomustine 1(2-chloroethyl)-3-cyclohexyl-l-nitrosourea (CCNU).

METHODS

Doses of 10 mg, 20 mg and 30 mg/Kg body weight of CCNU were injected intraperitoneally in separate groups of animals.

RESULTS

With 10 mg/Kg body weight of CCNU, serum bilirubin levels increased for up to 72 hours and then slowly returned to normal. With a dose of 20 mg/Kg body weight of CCNU, serum bilirubin, AST, ALT and alkaline phosphatase levels increased for 72 hours and then returned to normal over 4-5 weeks. With a dose of 30 mg/Kg body weight peak levels of serum bilirubin were reached on day 17. Pathological studies were carried out after injection of 30 mg/Kg body weight of CCNU. After 72 hours hepatocytes were normal, with minimal nonspecific inflammation and bile duct proliferation. After 16 days, triaditis was observed with deposition of collagen. Focal fibrosis was also noticed. There was no significant abnormality of hepatocytes. After 75 days, hepatocytes showed focal ballooning. Bile duct proliferation was seen invading the parenchyma. Nodules of hepatocytes separated by irregular fibrous bands indicated cirrhosis.

CONCLUSIONS

An animal model of intrahepatic cholestasis has been developed using CCNU; this model may be used to assess the utility of hepatobiliary radiopharmaceuticals.

Bone scans in neuroblastoma

Eighty-Six patients of neuroblastoma ranging in age from four months to 15 years were studied with 99m Tc-MDP for total skeletal survey over a period of seven years (1983-1990). The diagnosis of neuroblastoma was based on bone marrow examination, FNAC, lymph node biopsy, histopathology. Bone imaging was performed three hrs. after intravenous administration of 99m Tc-MDP. Out of 86 patients, 45 patients had positive bone scan showing osseous concentration in 122 sites and extraosseous concentration in 34 sites. Seven patients had liver metastases. None of these liver metastases showed concentration of MDP. Fourteen patients underwent surgery for the primary tumour at the time of bone scanning. Ten patients were studied at the time of follow up, of which four patients showed good response as bony metastases were not demonstrated on bone scintigraphy and X-rays. In conclusion, bone scan is an useful test in neuroblastoma in delineating the bony metastases and also in assessing the efficacy of chemotherapy in these patients.

Utility of technetium-t-butyl isonitrile (99mTc-TBI) myocardial imaging in coronary artery disease

99mTc-t-butyl isonitrile is a useful agent for myocardial perfusion imaging. The superior physical advantages of technetium over 201thallium make larger doses possible for imaging. Accumulation in the myocardium is unidirectional in that once attached it does not leave the myocardium and hence two separate injections are needed for rest and stress imaging. High liver uptake frequently conceals the inferior wall and high early uptakes make immediate post-injection imaging almost impossible at least up to 45-60 min. This agent, however, was seen to accurately identify under-perfused areas and distinguish between ischaemia and infarct in our patients. Agreement with 201Tl and with GBP study of regional wall motion was excellent. While its individual sensitivity and specificity are quite high at 82.6 and 90.9%, in combined GBP studies the sensitivity rose to 93.4%. It is concluded that Tc-TBI is a valuable agent for myocardial perfusion scintigraphy, especially in a developing country like India where Tc-MIBI cannot be routinely used, since it is expensive, and where regular supplies of 201Tl are also not always feasible due to the high cost of importing. 99mTc-TBI can be made cheaply here and in a select population, notably in those with left anterior descending and circumflex coronary artery disease, it can provide valuable information.

Regional distribution study of brain perfusion and metabolic agents in normal and tumour bearing rat brains using autoradiographic technique

Regional distribution of brain perfusion imaging agents, [131I]N,N,N'-trimethyl-N'-[2-hydroxy-3-methyl-5-iodobenzyl]1,3 propanediamine (HIPDM) and [131I]-N-isopropyl-p-iodoamphetamine (IMP), was compared with the distribution of patterns of [14C]L-methionine and [14C]D-glucose in normal and tumour bearing rat brains using autoradiographic technique. There was higher concentration of the radiopharmaceutical in grey than white matter in normal rat brain. Autoradiographs of brain tumour sections showed very low uptake of [131I]HIPDM and [131I]IMP as compared to normal brain tissue. There was moderate concentration of [14C]D-glucose and avid uptake of [14C]L-methionine in tumours. Autoradiographic study is useful for evaluating distribution patterns of radiopharmaceuticals.

Visualization of suppressed thyroid tissue by technetium-99m-tertiary butyl isonitrile: an alternative to post-TSH stimulation scanning

The autonomously functioning thyroid nodule (AFTN) is a discrete, nodular structure which operates independently of pituitary control and without relation to the remaining thyroid tissue. Presently, for the visualization of a suppressed thyroid lobe, a patient has to undergo the thyrotropin (TSH) stimulation test, which has several disadvantages. In this study we have used tertiary butyl isonitrile (99mTc-TBI), well known as a myocardial imaging agent, for visualization of the suppressed lobe. Thirteen of fourteen patients studied demonstrated a contralateral lobe on a 99mTc-TBI scan which was not visualized with a 99mTc0(4) or 131I scan. Although it is not possible to demonstrate the autonomous nature of the hyperfunctioning thyroid nodule using 99mTc-TBI, we conclude that it is feasible to use this agent to visualize the lobe without the TSH test.

Preparation and evaluation of 99mTc-t-butylisonitrile (99mTc-TBI) for myocardial imaging: a kit for hospital radiopharmacy

A previous method was modified to obtain [99mTc(TBI)6]+ by reacting Zn(TBI)2Br2 directly with 99mTcO4- in the presence of Sn2+ ions. [Cu(TBI)4]Cl was next used as a source of TBI. On reaction with 99mTcO4- and Sn2+ ions for 3 min at 100 degrees C, [99mTc(TBI)6]+ product of radiochemical purity greater than 90% and yield greater than 70% was obtained. Data of biodistribution in rats (2-2.5% in heart) and biokinetics in rabbits were satisfactory. The kit formulation was found to be stable and also safe for administration.

Clinical evaluation of 99mTc(V)-dimercapto succinic acid (DMSA) for imaging medullary carcinoma of thyroid and its metastasis

99mTc(V)-DMSA kits developed by the Radiopharmaceutical Division, Bhabha Atomic Research Centre, have been evaluated for potential use in scanning medullary carcinoma of the thyroid and its metastases. There were 15 patients with proved medullary carcinoma and 6 patients with other differentiated thyroid carcinoma. Amongst the 15 patients with medullary carcinoma, 12 (80%) showed positive localisation either in the primary or one or more metastatic sites. None of the six patients with carcinoma other than medullary showed increased concentration of 99mTc(V)-DMSA. Of the 37 known metastatic sites in 15 patients with medullary carcinoma, 24 showed concentration of 99mTc(V)-DMSA (64.9%). In addition, 99mTc(V)-DMSA concentration was seen in 14 sites where no evidence of metastasis was revealed. The incidence of 99mTc(V)-DMSA concentration in soft tissue and bone metastasis was similar.

Preparation and evaluation of 99mTc(V)-DMSA complex: studies in medullary carcinoma of thyroid

Consequent to the promising results reported with 99mTc(V)-DMSA for imaging certain types of soft tissue tumors, we have developed methods to prepare this radiopharmaceutical in three ways: from freshly prepared reagents, through the use of a two component kit and use of the standard renal DMSA kit by a modified recipe. The 99mTc(V)-DMSA complex has been subjected to paper electrophoretic and chromatographic procedures and also biodistribution studies. The distinctly different behaviour of this new product compared to that of the well known renal DMSA complex has been clearly established. Scintiimaging in a preliminary clinical trial in patients with medullary carcinoma of the thyroid has been encouraging.

Pitfalls in the lateral imaging of the thyroid with pinhole collimators

Imaging of the thyroid gland with pinhole collimators in the lateral projection is associated with the problem of count rate contribution from the contralateral lobe. In a series of experiments conducted using a thyroid-simulating phantom, the contribution of this nature was calculated. Radioisotopes of different energies such as 99mTc and 131I were used to see the effect of energy on this contribution. It was observed that the count rate contribution from the contralateral lobe to the lobe proximal to the collimator can be as high as 70% at a distance of 6 cm from the collimator. At distances more than 6 cm these contributions from the contralateral lobe are much more than this.

Pitfalls in the Lateral Imaging of the Thyroid with Pinhole Collimators

Imaging of the thyroid gland with pinhole collimators in the lateral projection is associated with the problem of count rate contribution from the contralateral lobe. In a series of experiments conducted using a thyroid-simulating phantom, the contribution of this nature was calculated. Radioisotopes of different energies such as 99mTc and 131I were used to see the effect of energy on this contribution. It was observed that the count rate contribution from the contralateral lobe to the lobe proximal to the collimator can be as high as 70% at a distance of 6 cm from the collimator. At distances more than 6 cm these contributions from the contralateral lobe are much more than this.

Scan appearances in hydatid cysts of the liver: analysis of 55 cases

Liver scans done at our Centre between 1964 and 1977 were analyzed with reference to hydatid cysts in liver. Among the approximately 7200 patients analyzed, there were 55 suspected to have hydatid cysts. The criteria adopted in screening the patients for hydatid cysts were based upon clinical findings and liver scan findings. The cases were analyzed with respect to their histologic findings, locations of cold areas in the liver, and correlation with Casoni's test. We found that 1) the cystic involvement was most often in the right lobe of the liver; 2) Casoni's test does not rule out or establish the presence of hydatidosis; 3) radioisotopic vascular studies done in some cases contributed to the diagnosis; 4) although a positive liver scan does not indicate the cause of the disease, the scans showing large and totally photon-deficient cold areas along with good general condition of the patients help in the diagnosis of hydatid cysts in the liver.

Efficacy of brain scanning in epilepsy of late onset

Brain scans of 513 patients with epilepsy of late onset were analysed with reference to the patient's age and sex and to the nature of convulsion. Only 17 of them showed an abnormal concentration of radionuclide indicating a space-occupying lesion in the brain. The findings of those patients who had positive brain scans were correlated with EEG findings. It was found that the incidence of epilepsy of late onset is almost 3 times higher in males than in females and that the age cannot be considered as a criterion for screening the patients for brain scan investigations as far as epilepsy of late onset is concerned. In our opinion, the incidence of 3.3% is not too low. A positive brain scan finding calls for further investigation and helps in deciding the management and further line of treatment of the patients. Moreover, a normal scan rules out the presence of a space-occupying lesion and helps as a screening procedure.

Efficacy of Brain Scanning in Epilepsy of Late Onset

Brain scans of 513 patients with epilepsy of late onset were analysed with reference to the patient's age and sex and to the nature of convulsion. Only 17 of them showed an abnormal concentration of radionuclide indicating a space-occupying lesion in the brain. The findings of those patients who had positive brain scans were correlated with EEG findings.

It was found that the incidence of epilepsy of late onset is almost 3 times higher in males than in females and that the age cannot be considered as a criterion for screening the patients for brain scan investigation as far as epilepsy of late onset is concerned.

In our opinion, the incidence of 3.3 % is not too low. A positive brain scan finding calls for further investigation and helps in deciding the management and further line of treatment of the patients. Moreover, a normal scan rules out the presence of a space-occupying lesion and helps as a screening procedure.

Radionuclide inferior vena cavagram

Routine visualisation of the I.V.C. at the time of injection for hepatosplenic scintigraphy may sometimes yield useful information. 4 such instances are reported.

Frequency of inferior vena caval abnormalcy due to a juxtaposed pathology

Radionuclide inferior vena cavagrams were done in 135 patients who had hepatomegaly, splenomegaly or a mass in the vicinity of the inferior vena cava (I.V.C.). 2-5mCi 66mTc phytate, 99mTc S colloid, 99mTc O4-, 99mTc-LIDA, 99mTc pyridoxyledene glutamate or 113mIn colloid were injected directly and rapidly into either a malleolar or a femoral vein while the patient lay supine under the 13.5'' detector head of a scinticamera. Rapid sequential scintiphotos were manually taken at approximately 1 sec. interval for 20-30 sec. Thus iliac vein, I.V.C., cardiopulmonary zone in infants, aorta and the arterial phase were visualized. 48% of these subjects had an abnormal I.V.C. and the depictions were interestingly varied, indicating that different patients responded in a different manner even to grossly similar pathologies. It became evident that this soft walled vessel could be compressed by both fluids and neoplastic tissue (Fig. 1, 2); the long I.V.C. channel could also be segmentally pushed away by a mass in its vicinity. (Fig. 2, 3, 4). An abnormal arterial flush usually differentiated between benign (Fig. 2) and malignant (Fig. 3) lesions, even when the mass was extra-hepatic (Fig. 4) and retiroperitoneal (Fig. 5). Such a systematic study of I.V.C. had not been possible earlier since the classical x-ray contrast inferior vena cavagram necessitates venous dissection, passage of a catheter, and the injection of large volume of fluid under an unphysiologically high pressure. The simplified radionuclide technique, however, permitted the study of neonates and critically ill subjects with massive ascites, while retaining a satisfactory reproducability.