Undiagnosed retroperitoneal mass. Report of a case in which needle aspiration cytodiagnosis led to investigation and timely management

Needle aspiration cytology of an undiagnosed retroperitoneal mass was performed on a 37-year-old male. The cytologic findings were highly consistent with a seminoma. In the differential diagnosis the possibility of non-Hodgkin's lymphoma, melanocarcinoma and metastatic adenocarcinoma was considered. The cytologic features in the aspirate included uniform, single to loose groups of malignant cells with round nuclei and prominent nucleoli and pale cytoplasm with occasional vacuoles. A variable number of lymphocytes were intermingled with the neoplastic cells. On immunostaining, the markers for lymphoma, melanoma and epithelial malignancy were negative, while alpha-1-antitrypsin was positive in malignant cells, and alkaline phosphatase activity was weakly positive in the cytoplasm. In view of the cytologic diagnosis, a clinical examination of the testes was undertaken and followed by an ultrasound examination, which demonstrated a well-demarcated tumor in the left testis. It was removed and diagnosed as a typical seminoma. This case is of interest since needle aspiration cytodiagnosis not only suggested the correct diagnosis in an otherwise-undiagnosed retroperitoneal mass but also led to a timely investigation and correct management.

Method for quantitation of IgG subclass antibodies in mouse serum by enzyme-linked immunosorbent assay

One of the methods for calibration of antigen specific antibodies in a serum involves parallel titration of known concentrations of purified normal immunoglobulins (Igs) and a specific antiserum. We evaluated the effect of three methods for capturing known concentrations of purified normal mouse Igs (IgG, IgG subclasses and IgM) on the anti-tetanus toxoid antibody concentrations assigned to a reference mouse serum: (1) direct coating, (2) capture by pre-coated anti-mouse IgG (Fc) specific antibodies, and (3) capture by pre-coated anti-mouse IgG (Fab) specific antibodies. Direct coating of purified Igs onto plastic was the least efficient and would greatly overestimate antigen specific antibody concentrations. Equivalent concentrations of purified IgG subclasses and IgM produced higher absorbances when captured by anti-Fab antibodies pre-coated on plates than by anti-Fc antibodies. As a consequence, the anti-Fc capture method resulted in the assignment of IgG1, IgG2a and IgG2b tetanus specific antibody concentrations which exceeded the total IgG1, IgG2a and IgG2b concentrations. Additionally, the sum of tetanus specific IgG subclass antibodies exceeded the tetanus specific IgG antibody concentration by > 2-fold. In contrast, the anti-Fab capture method resulted in 2-9-fold lower assigned tetanus antibody concentrations which did not exceed the total Ig concentrations. We conclude that when using enzyme-linked immunosorbent assays, parallel titration of purified normal Ig standards captured by anti-Fab antibodies is superior to anti-Fc capture or direct coating for calibrating antigen specific antibodies in a reference serum.

5-fluorouracil induced cardiotoxicity in albino rats

Since 1975, many cases of 5-fluorouracil (5-FU) associated cardiotoxicity have been described in the literature. A histopathological study of 5-FU induced cardiotoxicity was performed on 50 Swiss albino rats. Multiple interstitial myocardial hemorrhages, multifocal myofibre necroses, inflammatory reaction, vascular changes, valvulitis and pericarditis have been noted especially in the left heart ventricles of rats under study. The mechanism of 5-FU associated cardiotoxicity is controversial. A probable mechanism has been proposed; it explains the endothelial damage leading to extravasation of the drug containing blood into myocardium resulting in myofibre necroses and inflammatory reaction.

Ultrasound guided percutaneous fine needle aspiration cytology of pancreas: a review of 61 cases

The study includes 61 cases which were subjected to ultrasound (US) guided fine needle aspiration cytology (FNAC) to find out the utility of this technique in the diagnosis of pancreatic lesions. Age of the patients ranged from 23 to 85 years with a median of 50 years. Male to female ratio was 36:25. One or more clinical diagnoses were offered in 16 and in 9 of these, the disease was related to pancreas. Subsequent to US, the lesions were localized to pancreas in 57 and the nature of pathology in the pancreatic lesion could be diagnosed in 31. By FNAC, 31 cases (50.8%) were diagnosed to have pancreatic malignancy which included adenocarcinoma (23 cases), papillary cystic tumour (1), muco-epidermoid carcinoma (1), acinic cell carcinoma (1), islet cell tumor (1), and non Hodgkin lymphoma (4). FNAC of liver in 2 cases and retroperitoneal lymph node in a case of pancreatic adenocarcinoma revealed metastasis. During follow up, 1 case of non Hodgkin's lymphoma showed CSF involvement. Three cases (4.9%) were suspected to have epithelial malignancy of which one was confirmed as an adenocarcinoma following surgery and histology. Four (6.6%) were benign lesions which included nonspecific inflammation (2 cases), tuberculous pancreatitis (1) and pseudopancreatic cyst (1). The remaining 23 cases (37.7%) had normal or inadequate cytology. Of these, FNAC of liver showed metastasis in 2 cases and one case each were diagnosed as adenocarcinoma and pseudopancreatic cyst respectively following surgery. None of the patients had any complication following FNAC. We recommend US guided FNAC to be routinely used for diagnosis of pancreatic lesion.

Development of a guinea pig model to assess immunogenicity of Haemophilus influenzae type b capsular polysaccharide conjugate vaccines

There is currently no animal model which reliably predicts the immunogenicity of Haemophilus influenzae type b (Hib) polysaccharide-protein conjugate vaccines in human infants. We evaluated various Hib vaccines in guinea pigs using techniques similar to the United States potency test for adsorbed diphtheria and tetanus toxoids with a view to developing a method for evaluating the potency of a combined adsorbed tetanus, diphtheria, pertussis and Hib conjugate vaccine. Groups of 6-8 guinea pigs received 1.5 single human doses of vaccine at 0 and at 6 or 8 weeks and were bled at 6 weeks and 2 weeks after the booster injection. Total antibodies to polyribosylribitolphosphate (PRP), the Hib capsular polysaccharide, were measured in individual animals and in serum pools by radioimmunoassay. The relative antibody responses of guinea pigs to Hib conjugate vaccines qualitatively resembled those of human infants. Unconjugated polysaccharide was not immunogenic; PRP-D produced a low antibody response, HbOC, PRP-T (Merieux) and Hib-T (MPMBL) produced a low response to the first dose and a strong anamnestic response to the booster (geometric mean anti PRP > 1 micrograms ml-1). PRP-OMP uniquely produced a strong response after the first dose which was further boosted by the second dose. Experimental Hib-T vaccine lots with low levels of conjugation were poorly immunogenic in guinea pigs. Combinations of DTP and Hib-T vaccines showed equivalent or greater immunogenicity than Hib-T alone. We propose that the guinea pig model may be useful to verify the immunogenicity of PRP conjugate vaccines and for pre-clinical evaluations of DTP-Hib combination vaccines containing PRP conjugates.

Brain metabolite changes on in vivo proton magnetic resonance spectroscopy in children with congenital hypothyroidism

Localized in vivo proton magnetic resonance spectroscopy and imaging were performed in five children with untreated congenital hypothyroidism to look for biochemical markers of abnormal myelin and neuronal development. The patients had high levels of choline-containing compounds, which returned to normal with euthyroidism. These metabolic alterations may reflect blocks in myelin maturation that are reversible by thyroid hormone replacement throughout childhood.

Role of brain [Mg2+]i in alcohol-induced hemorrhagic stroke in a rat model: a 31P-NMR in vivo study

One hundred percent of anesthetized rats administered 6.6 gm/kg of ethanol IP died within 10-35 min of alcohol injection; upon autopsy of the brain all demonstrated profound subarachnoid and intracranial bleeding, clear signs of hemorrhagic stroke. Pretreatment of rats with 4 mumol/min MgCl2, but not saline, via IV administration (for 30-45 min), prevented hemorrhagic stroke in all animals so treated with 6.6 gm/kg ethanol. Administration of the stroke dose of alcohol resulted in rapid (within 3-5 min) and marked deficits in whole brain intracellular free Mg ([Mg2++]i) as observed by in vivo 31P-NMR spectroscopy. Intracellular pH (pHi) and the phosphocreatine [PCr]/[ATP] ratio also fell following a significant fall in brain [Mg2+]i). Brains of rats that exhibited strokelike events, upon death and autopsy, demonstrated continued and marked intracellular acidosis with progressive fall in the [PCr]/[ATP] ratio and elevation of inorganic phosphate (Pi) and [H+]i; these events were not accompanied by any rises in systemic arterial blood pressure. Rats pretreated with MgCl2 exhibited relatively stable brain [Mg2+]i, and essentially unchanged pHi, [PCr], [ATP], or [Pi] following alcohol administration, although such animals exhibited threefold alterations in plasma Mg2+, as measured by ion selective electrodes. These observations suggest that high alcohol ingestion can result in severe vasospasm, ischemia, and rupture of blood vessels probably as a consequence of depletion of brain [Mg2+]i, events that can be prevented by Mg2+ pretreatment.

Acute bilateral ophthalmoplegia secondary to metastatic prostatic carcinoma. Demonstration on magnetic resonance imaging

We report an unusual case of acute bilateral ophthalmoplegia secondary to bilateral cavernous sinus metastasis from prostatic adenocarcinoma. The lesion was demonstrated with magnetic resonance imaging.

In vivo proton magnetic resonance spectroscopy in a case of intracranial hydatid cyst

We performed in vivo proton magnetic resonance spectroscopy (MRS) in a patient who had an intracranial hydatid cyst. Besides lactate, alanine, and acetate, a large resonance for pyruvate was observed. These findings were further confirmed by ex vivo high-resolution NMR spectroscopy of the evacuated cyst fluid, as well as of the fluid aspirated from a cyst in the liver of the same patient. The MRS pattern appeared different from that seen in other cystic lesions of the CNS. In vivo MRS may be used as an adjunct to imaging in the diagnosis of intracranial hydatid cysts. It may also have a role in monitoring drug therapy.

Respiratory distress in newborn: treated with ventilation in a level II nursery

Fifty consecutive neonates with respiratory distress persisting beyond 6 h of age were studied during a 18 month period (total deliveries 2000/y). Twenty two neonates were managed with oxygen hood with increasing oxygen concentration, 28 with continuous positive airway pressure (CPAP) ventilation using a nasal cannula. Of these babies on CPAP, 10 were shifted to intermittent positive pressure ventilation (IPPV) on a pressure limited, time cycled ventilator (Neovent, Vickers). Babies were monitored with continuous hemoglobin oxygen saturation (SaO2), hourly blood pressure and vital charting. Radial arterial blood gas analysis (ABG) was done when feasible and especially on clinical deterioration. Oxygen (FiO2 0.95) from an oxygen concentrator was used as a source of continuous supply of oxygen. Commonest cause of respiratory distress was hyaline membrane disease (18%), followed by wet lung syndromes (14%), meconium aspiration (12%), asphyxia (12%) and septicemia (8%). In 8 babies, a lung biopsy (postmortem) was done to confirm the diagnosis. Nineteen of the 50 babies with respiratory distress died, there was a survival of 50% on CPAP and 30% on IPPV. No case of oxygen toxicity or other major complications was encountered. Even with moderate resources, neonatal ventilation in a Level II nursery is a challenging task. Babies less than 1000g require aggressive measures which is not very economical in a special care baby unit (SCBU).

Retinoblastoma with micrometastasis to CSF

A 28 mth old male presented with a squint and leukocoria. Clinical examination and computerized tomography (CT) suggested a unilateral retinoblastoma with distal optic nerve involvement. Investigations for distant metastasis including lumbar puncture cytology were negative. The eye was enucleated and 12 mm of optic nerve was excised via a combined neurosurgical/ophthalmological approach. Histopathological examination confirmed the optic nerve to the point of excision was free of tumor. However, cytology of cerebrospinal fluid (CSF) from the Sylvian fissure, taken at the time of surgery, revealed malignant retinoblastoma cells. The patient was treated with intrathecal and intravenous chemotherapy, and cranial radiotherapy. He is alive and well 4 yrs later. This case displays the importance of CSF cytology from the Sylvian fissure, as it dramatically changed the management and prognosis for the child. The role of lumbar puncture cytology in excluding CSF micrometastasis can be unreliable. A neurosurgical approach to the optic nerve has the potential to gain access to a long length of optic nerve, should it be involved with tumor, and also allows direct CSF sampling.

Myelomatous pleural effusion

Pleural effusion due to myelomatous involvement is rare. We are describing such a case who also had soft tissue extension from iliac bone with congestive heart failure.

Cystic intracranial mass lesions: possible role of in vivo MR spectroscopy in its differential diagnosis

Thirty-four patients showing cystic intracranial mass lesions on MR imaging were evaluated by in vivo proton MR spectroscopy (MRS) with the aim of detecting lesion-specific spectral patterns that may assist imaging in better tissue characterization. In vivo spectroscopy was performed using stimulated echo acquisition mode with echo times 20 and 270 m in all, and spin echo with echo time 135 m in 11 patients. All primary neoplasms (intra-as well as extra-axial) showed choline (3.22 ppm) resonance along with lipid and/or lactate (1.3 ppm). It was not possible to grade cystic gliomas based on N-acetyl asparate-to-choline ratio. High-grade gliomas (n = 8) showed lipid/lactate and low-grade gliomas (n = 6) showed only lactate. Seven patients with brain abscess showed resonances only from acetate (1.92 ppm), lactate (1.3 ppm) and alanine (1.5 ppm). Two cases of metastatic adenocarcinoma showed only lipid/lactate. In 7 patients with epidermoid cyst, lactate along with an unassigned resonance at 1.8 ppm was observed and could be easily differentiated from arachnoid cysts (n = 2), which showed only minimal lactate. A case of cystic meningioma could be differentiated from cystic schwannoma by the presence of alanine in the former. It is concluded that MR imaging, when combined with in vivo MRS, may help to better characterize intracranial cystic mass lesions.

Adjuvant properties of aluminum and calcium compounds

It is likely that aluminum compounds will continue to be used with human vaccines for many years as a result of their excellent track record of safety and adjuvanticity with a variety of antigens. For infections that can be prevented by induction of serum antibodies, aluminum adjuvants formulated under optimal conditions are the adjuvants of choice. It is important to select carefully the type of aluminum adjuvant and optimize the conditions of adsorption for every antigen since the degree of adsorption of antigens onto aluminum adjuvants markedly affects immunogenicity. The mechanism of adjuvanticity of aluminum compounds includes formation of a depot at the site of injection from which antigen is released slowly; stimulation of immune-competent cells of the body through activation of complement, induction of eosinophilia, and activation of macrophages; and efficient uptake of aluminum-adsorbed antigen particles by antigen-presenting cells because of their particulate nature and optimal size (< 10 microns). Limitations of aluminum adjuvants include local reactions, production of IgE antibodies, ineffectiveness for some antigens, and inability to elicit cell-mediated immune responses especially cytotoxic T-cell responses. Calcium phosphate, which has adjuvant properties similar to aluminum adjuvants, has the potential advantages of being a natural component of the body and of not increasing IgE production. There is a need for alternative adjuvants, particularly for diseases in which cell-mediated immune responses are important for prevention or cure.

Effectiveness of cryosurgery in xanthelasma palpebrarum

100 cases of xanthelasma palpebrarum were subjected to closed probe cryosurgery using nitrous oxide gas as the cryogen. Each freeze thaw cycle was fixed for 15 seconds. The procedure was done in a single session in all the cases. All these cases were followed up for 6 months. At the end of 6 months follow up in 68 cases, treated sites looked absolutely normal, in other 6 cases, treated sites looked almost normal except for pin head sized hypopigmentation in the centre of their treated lesions, while in remaining 26 cases, recurrence was observed in the form of yellowish papules/plaques. No other sequelae in the form of scarring or milia were observed in any case.

Hepatoblastoma in an adult with biliary obstruction and associated portal venous thrombosis

We present a case of adult hepatoblastoma. This young female presented with severe acute cholangitis. Preoperative diagnosis was common bile duct (CBD) obstruction with portal vein thrombosis. On exploration she had a tumor mass in the CBD. The unusual features of this case are discussed in this report.

In vivo localized proton magnetic resonance spectroscopy of intracranial tuberculomas

In vivo proton magnetic resonance spectroscopy (MRS) was performed in ten patients with intracranial tuberculomas with the aim of finding biochemical finger prints which may help in the noninvasive diagnosis of the disease. Diagnosis of tuberculoma was confirmed in all these cases retrospectively. Ex vivo spectroscopy of formalin fixed samples of four granulomas and a normal brain (cerebellar) tissue, was performed to confirm the in vivo resonances. The in vivo study showed resonance at 1.3 ppm and 0.9 ppm assigned to methylene group (CH2)n and terminal methyl groups (-CH3) of fatty acids respectively which was subsequently confirmed by the ex vivo study. Large resonances of fatty acids in in vivo study appeared to be due to high lipid content of caseous material. It is concluded that in vivo proton spectroscopy may be helpful in differentiating tuberculomas from other intracranial mass lesions which have diagnostic difficulties on MR imaging.

Evaluation of the laboratory mouse model for screening topical mosquito repellents

Eight commercial repellents were tested against Aedes aegypti 0 and 4 h after application in serial dilution to volunteers and laboratory mice. Results were analyzed by multiple regression of percentage of biting (probit scale) on dose (logarithmic scale) and time. Empirical correction terms for conversion of values obtained in tests on mice to values expected in tests on human volunteers were calculated from data obtained on 4 repellents and evaluated with data obtained on 4 others. Corrected values from tests on mice did not differ significantly from values obtained in tests on volunteers. Test materials used in the study were dimethyl phthalate, butopyronoxyl, butoxy polypropylene glycol, MGK Repellent 11, deet, ethyl hexanediol, Citronyl, and dibutyl phthalate.