The marijuana-schizophrenia multifaceted nexus: Connections and conundrums towards neurophysiology

Delta-9-tetrahydrocannabinol, a component of marijuana, interacts with cannabinoid receptors in brain involved in memory, cognition, and emotional control. However, marijuana use and schizophrenia development is a complicated and contentious topic. As a result, more investigation is needed to understand this relationship. Through the functional enrichment analysis, we report the delta-9-tetrahydrocannabinol to manipulate the homeostatic biological process and molecular function of different macromolecules. Additionally, using molecular docking and subsequent processing for molecular simulations, we assessed the binding ability of delta-9-tetrahydrocannabinol with the estrogen-related protein, dopamine receptor 5, and hyaluronidase. It was found that delta-9-tetrahydrocannabinol may have an impact on the brain's endocannabinoid system and may trigger the schizophrenia progression in vulnerable people. Delta-9-tetrahydrocannabinol may interfere with the biological function of 18 proteins linked to schizophrenia and disrupt the synaptic transmission (dopamine, glutamine, and gamma-aminobutyric acid). It was discovered that it may affect lipid homeostasis, which is closely related to membrane integrity and synaptic plasticity. The negative control of cellular and metabolic processes, fatty acids binding /activity, and the manipulated endocannabinoid system (targeting cannabinoid receptors) were also concerned with delta-9-tetrahydrocannabinol. Hence, this may alter neurotransmitter signaling involved in memory, cognition, and emotional control, showing its direct impact on brain physiological processes. This may be one of the risk factors for schizophrenia development which is also closely tied to some other variables such as frequency, genetic vulnerability, dosage, and individual susceptibility.

Demographics and appropriateness of cellular blood component irradiation practices: Ambispective analysis from a tertiary care center

BACKGROUND

Transfusion-associated graft versus host disease (TA-GVHD) is often underreported. There may also be lapses in TA-GVHD prevention practices due to lack of revision of some of the existing clinical guidelines as well as limited audits on practices of blood component irradiation. This study was undertaken to highlight these shortcomings, and generate data for development of institutional guidelines.

METHODS/MATERIALS

Study cohort was selected from patients requiring transfusion support during June 2019 to May 2020. Transfusion history of these patients were followed, both retrospectively and prospectively till July 2021. Transfusion requisitions were categorized as IR (with request for irradiation) or NIR (with no request for irradiation) and justified or unjustified according to published international guidelines.

RESULTS

Total 6963 requisitions for cellular blood components were received from 255 patients included in the study cohort. Of these, 3690 (54.9 %) were IR requisitions, while remaining 3029 (45.1 %) requisitions were NIR. Overall, 4242 (63.1 %) requisition were justified for their irradiation status as per published guidelines and 1595 (23.8 %) were found to be Unjustified while justification could not be assessed for remaining 882 (13.1 %) of the requisitions. The highest proportion of Unjustified demands in NIR requisitions was observed in patients with Severe Aplastic anemia (59.4 %).

CONCLUSION

Many units were unnecessarily irradiated (7.7 %) while irradiation was missed in 16 % of the requisitions included in analysis which may be attributed to lack of institutional guidelines. We recommend that every centre should adopt a published well-researched guideline including amendments based on review of practices at their center.

Statistical model for prediction of ABO hemolytic disease of the fetus and newborn in India

ABO incompatibility is the most common cause of immune hemolytic disease of the fetus and newborn (HDFN). The American Academy of Pediatrics lists blood group incompatibility as one of the major risk factors for severe hyperbilirubinemia in newborns. We have estimated the risk of ABO HDFN to determine the need for its routine screening. Blood group data from all blood donors who donated in the last 10 years were collected and analyzed. The population prevalence of ABO blood group genes using the phenotype data of blood donors was estimated. This information was further used to calculate an incidence of ABO HDFN requiring intervention in the population. ABO blood group typing was analyzed in 425,743 blood donors. The ABO phenotypes of A, B, O, and AB were 22.48, 36.73, 31.59, and 9.2 percent, respectively. The gene frequencies were 0.1733, 0.2647, and 0.5620 for A, B, and O, respectively. It was estimated that 13.84 percent of group O women would give birth to a non-group O baby and that approximately 2.77 percent of deliveries would likely have ABO HDFN in the study population. In India, the estimated risk of ABO HDFN is 2.9 percent, with a daily 2196 babies at risk of ABO HDFN requiring intervention. This analysis estimates the overall burden of ABO HDFN in the population, which could aid in the decision-making of policymakers, physicians, and community health practitioners to improve neonatal care.

ABO incompatibility is the most common cause of immune hemolytic disease of the fetus and newborn (HDFN). The American Academy of Pediatrics lists blood group incompatibility as one of the major risk factors for severe hyperbilirubinemia in newborns. We have estimated the risk of ABO HDFN to determine the need for its routine screening. Blood group data from all blood donors who donated in the last 10 years were collected and analyzed. The population prevalence of ABO blood group genes using the phenotype data of blood donors was estimated. This information was further used to calculate an incidence of ABO HDFN requiring intervention in the population. ABO blood group typing was analyzed in 425,743 blood donors. The ABO phenotypes of A, B, O, and AB were 22.48, 36.73, 31.59, and 9.2 percent, respectively. The gene frequencies were 0.1733, 0.2647, and 0.5620 for A, B, and O, respectively. It was estimated that 13.84 percent of group O women would give birth to a non–group O baby and that approximately 2.77 percent of deliveries would likely have ABO HDFN in the study population. In India, the estimated risk of ABO HDFN is 2.9 percent, with a daily 2196 babies at risk of ABO HDFN requiring intervention. This analysis estimates the overall burden of ABO HDFN in the population, which could aid in the decision-making of policymakers, physicians, and community health practitioners to improve neonatal care.

Patterns of Orthopaedic Injuries among Motorbike Accident Admissions Presenting to a Tertiary Care Hospital in Kathmandu

BACKGROUND

The anecdotal burden of morbidity secondary to motorbike accidents is thought to enormous by personnel involved in trauma care. The objective of the present study is to ascertain patterns and association of injuries and causes of mortality in a cohort of motorbike accident victims.

METHODS

A retrospective chart review of 1337 motorbike accident admissions B and B Hospital in Kathmandu between January 2009 and December 2010 was undertaken.

RESULTS

Majority of victims were between 20 to 50 years [1230 (92%) males]. Lower extremity injuries comprised on 816 (61% of total admissions). Tibia fractures were the most common injury in isolation, multiple injury, as well as polytrauma, and a vast majority of these were open fractures. Multiple injuries were seen in 82 (6.1%) patients and 33 (2.5% of Total) patients were polytraumatized. An amputation was necessary in 16 (1.2%) patients and emergent fasciotomy for compartment syndrome was necessary in 23 (1.7%) cases of tibia fractures and 39 (2.2%) of foot and ankle injuries. A floating joint injury was present in 24 (1.8%) patients.. A fat embolism syndrome (FES) was diagnosed in 8 (0.6%) patients. The overall mortality was 0.45% (6 patients).

CONCLUSIONS

Motorbike accident is an important cause of morbidity and mortality in Kathmandu, and often involves a very productive age group. There is an imminent need to address this public health problem.

Extra and Intra-articular Synovial Chondromatosis

Synovial chondromatosis is not so rare intra-articular condition secondary to synovial metaplasia, that affects the knee joint. Extra-articular synovial chondromatosis however is an extremely rare condition that usually involves the synovial sheath or bursa of the foot or hand. We present two cases of synovial chondromatosis, one intra and one extra-articular. The first case was a 25 year old lady who presented with pain, swelling and restricted range of motion of left knee and was found to have an intra-articular synovial chondromatosis which was treated successfully by joint debridement. The second case was that of a 22 year old man who presented with right knee pain and was diagnosed to have an extra-articular synovial chondromatosis of his right medial hamstring tendon sheath, excision of which resulted in complete relief of symptoms.

Autoimmune hemolytic anemia: From lab to bedside

Autoimmune hemolytic anemia (AIHA) is not an uncommon clinical disorder and requires advanced, efficient immunohematological and transfusion support. Many AIHA patients have underlying disorder and therefore, it is incumbent upon the clinician to investigate these patients in detail, as the underlying condition can be of a serious nature such as lymphoproliferative disorder or connective tissue disorder. Despite advances in transfusion medicine, simple immunohematological test such as direct antiglobulin test (DAT) still remains the diagnostic hallmark of AIHA. The sensitive gel technology has enabled the immunohematologist not only to diagnose serologically such patients, but also to characterize red cell bound autoantibodies with regard to their class, subclass and titer in a rapid and simplified way. Detailed characterization of autoantibodies is important, as there is a relationship between in vivo hemolysis and strength of DAT; red cell bound multiple immunoglobulins, immunoglobulin G subclass and titer. Transfusing AIHA patient is a challenge to the immunohematologist as it is encountered with difficulties in ABO grouping and cross matching requiring specialized serological tests such as alloadsorption or autoadsorption. At times, it may be almost impossible to find a fully matched unit to transfuse these patients. However, transfusion should not be withheld in a critically ill patient even in the absence of compatible blood. The “best match” or “least incompatible units” can be transfused to such patients under close supervision without any serious side-effects. All blood banks should have the facilities to perform the necessary investigations required to issue “best match” packed red blood cells in AIHA. Specialized techniques such as elution and adsorption, which at times are helpful in enhancing blood safety in AIHA should be established in all transfusion services.

Root cause analysis of transfusion error: identifying causes to implement changes

BACKGROUND

As part of ongoing efforts to improve transfusion safety, an error reporting system was implemented in our hospital-based transfusion medicine unit at a tertiary care medical institute. This system is based on Medical Event Reporting System-Transfusion Medicine (MERS-TM) and collects data on all near miss, no harm, and misadventures related to the transfusion process. Root cause analyses of one such innocuous appearing error demonstrate how weaknesses in the system can be identified to make necessary changes to achieve transfusion safety.

STUDY DESIGN AND METHODS

The reported error was investigated, classified, coded, and analyzed using MERS-TM prototype, modified and adopted for our institute.

RESULTS

The consequent error was a "mistransfusion" but a "no-harm event" as the transfused unit was of the same blood group as the patient. It was a high event severity level error (level 1). Multiple errors preceded the final error at various functional locations in the transfusion process. Human, organizational, and patient-related factors were identified as root causes and corrective actions were initiated to prevent future occurrences.

CONCLUSION

This case illustrates the usefulness of having an error reporting system in hospitals to highlight human and system failures associated with transfusion that may otherwise go unnoticed. Areas can be identified where resources need to be targeted to improve patient safety.

Multicenter evaluation of individual donor nucleic acid testing (NAT) for simultaneous detection of human immunodeficiency virus -1 & hepatitis B & C viruses in Indian blood donors

BACKGROUND & OBJECTIVE

India has a high prevalence of HIV-1, hapatitis C and B virus (HCV and HBV) in the blood donors but has yet to implement nucleic acid testing (NAT) in blood screening. We undertook a multicentre evaluation of blood donor testing by NAT for simultaneous detection of HIV-1, HBV and HCV in a single tube and also to determine the feasibility of NAT implementation in India's low volume setting.

METHODS

A total of 12,224 unlinked samples along with their serological results were obtained from representative eight blood banks in India and were individually manually tested by the Procleix Ultrio Assay (Chiron Corp. Emeryville, CA) for simultaneous detection of HIV-1, HCV, and HBV.

RESULTS

Of the 12,224 samples tested, 209 (1.71%) were seroreactive. One hundred thirty three samples (1.09%) were reactive by Ultrio assay, 84 samples were seroreactive but NAT non reactive. There were eight NAT yield cases: 1 HIV, 1 HIV-HCV co-infection, and 6 HBV.

INTERPRETATION & CONCLUSION

Our observed NAT yield for all three viruses was 1 in 1528 (0.065%). We estimate NAT could interdict 3272 infectious donations a year among our approximate 5 million annual donations.

The CT appearances of gallbladder perforation

Perforation of the gallbladder is an uncommon complication of acute cholecystitis that is associated with relatively high mortality. Symptoms and clinical signs can be indistinguishable from those of uncomplicated acute cholecystitis, leading to delayed diagnosis. We reviewed the clinical and imaging findings in 17 patients with gallbladder perforation confirmed at surgery.

Effect of gamma irradiation on blood from glucose 6 phosphate dehydrogenase deficient blood donors

Recently, the irradiation of cellular blood components has received increased attention. Normal red blood cells (RBC) when subjected to gamma irradiation show increase in haemolysis and increased storage lesions. Glucose 6 phosphate dehydrogenase (G6PD) deficient blood is lacking in anti-oxidant properties which protect the RBC membrane and therefore when subjected to gamma irradiation, it may lead to increased haemolysis. In this study, 500 healthy non-remunerated blood donors were screened for G6PD deficiency. About 350 ml of whole blood was collected from 10 G6PD deficient donors (cases) and 10 units were collected from donors who were not deficient for G6PD (controls). All units were subjected to gamma irradiation of 25 Gy by a self contained gamma cell irradiator (Nordion Canada) on day 0 and then stored at 4 degrees C. Sampling was done from these cases and controls on day 0, 7, 14 and 21. Estimation of free plasma hemoglobin (Hb), free plasma potassium (K) and lactate dehydrogenase (LDH) was performed. It was found that there were no significant changes between the cases and controls in any of the parameters assessed, although the values for all the parameters were higher in case group at the end of storage period, these differences were not statistically significant.

Blood-fluid levels in the brain

17 cases reviewed prospectively over a period of 4 months highlight the varied appearance of blood-fluid levels in intracranial cystic lesions of different aetiologies; a finding which has not featured significantly in the medical literature. Four types of intracranial cysts demonstrating blood-fluid levels have been categorised according to the nature of the pathology, i.e. primary neoplasms of the brain, metastatic deposits to the brain in cases of extraneural malignancies, lesions of vascular aetiology and intraparenchymal bleeds secondary to trauma. The group of four primary intracranial neoplasms lists an oligodendroglioma, a recurrent tumour in a case of Von Hippel-Lindau syndrome, a Grade 3 astrocytoma and an acoustic schwannoma. Four cases of metastatic deposits to the brain were each secondary to primary malignant neoplasms of the breast, liver, ovary and lung. Of seven cases of a vascular aetiology, three resulted from arterial infarction, two from hypertension and one each from venous infarction and following anticoagulant therapy. Intracranial cysts within tumours have been postulated to occur secondary to a breakdown of the blood-brain barrier (BBB) rather than as a result of tumoural degeneration, as was thought probable earlier.

Application of gel technology in the serologic characterization of autoantibody in DAT-positive autoimmune diseases

Gel tests are now available for the determination of immunoglobulin classes and subclasses and complement fractions coating RBCs. These tests simplified serologic characterization of autoantibodies in various autoimmune diseases. The aim of this study was to evaluate the use of gel cards in the serologic characterization of autoantibody with regard to the immunoglobulin classes, complement fractions, and IgG subclasses, and the influence of these characteristics on hemolysis. Gel cards were used to characterize the RBC-bound autoantibodies in 66 DAT-positive patients. Hematologic and biochemical parameters such as Hb, reticulocyte count, serum bilirubin, and serum LDH were obtained from the patient files. Of the 49 patients carrying IgG on their RBCs, 21 (42.8%) were suffering from connective tissue disorders and another 16 patients (32.7%) had autoimmune hemolytic anemia. A total of 19 of these 49 patients had evidence of hemolysis. Thirteen of the 17 patients (76.5%) whose RBCs were coated with more than one type of immunoglobulin and complement were experiencing hemolysis (p < 0.05). Seventy-five percent (21 of 28) of patients having IgG1, IgG3, or both on their RBCs showed hemolysis (p < 0.05). Thus, it is important to serologically characterize autoantibodies in autoimmune disorders to effectively predict the prognosis and disease outcome. This characterization can be performed effectively with the gel test, which can be introduced in blood centers as a replacement to the conventional tube technique.

Factors influencing yield of plateletpheresis using intermittent flow cell separator

Platelet recovery in the recipient is influenced by the transfused dose of platelets, which in turn is dependent on the quality of single donor platelets (SDPs) in terms of platelet yield. Various donor factors such as predonation platelet count and Hemoglobin (Hb) concentration affect the platelet yield. A total of 61 plateletpheresis procedures performed on intermittent flow cell separator (MCS3p, Hemonetics) were evaluated for platelet yield. A relationship between predonation platelet count and Hb concentration with yield of platelets was studied using Pearson Correlation. The mean platelet yield was 2.9 +/- 0.64 x 10(11). While a direct relationship was observed between predonation platelet count and yield (r = 0.51, P < 0.001), no such correlation was noticed with donor Hb concentration (r = -0.05, P > 0.005). The yield was > or =3 x 10(11) in >80% of procedures when the predonation platelet count was > or =250 x 10(3)/mm. Optimization of platelet yield, which is influenced by predonation platelet count, is an emerging issue in blood transfusion services. However, further studies in this regard are needed using more advanced cell separators.

Effect of pre-storage gamma irradiation on red blood cells

BACKGROUND & OBJECTIVE

The irradiation of blood components has received increased attention due to increasing categories of patients eligible to receive such blood to prevent transfusion-associated graft versus host disease. Irradiation leads to enhancement of storage lesions, which could have deleterious effects when such blood is transfused. The aim of the present study was to assess the biochemical changes during conventional preservation of irradiated and non-irradiated whole blood.

METHODS

Ten units of whole blood were taken from healthy donors and divided into two parts. One aliquot was subjected to gamma irradiation and then stored under conventional blood banking conditions. Sampling was done from these irradiated and non-irradiated blood bags and tests for free plasma haemoglobin, plasma potassium and lactate dehydrogenase (LDH) were performed.

RESULTS

A progressive increase in the mean values of plasma Hb, K+ and LDH was seen in both the groups. The increase was statistically significant.

INTERPRETATION & CONCLUSION

Our findings indicated that the gamma irradiation of blood resulted in increased plasma haemoglobin, potassium and LDH. These biochemical changes might not have clinical significance when irradiated blood is transfused to a select group of patients. There is a need for further in vivo studies to follow up the consequences of transfusion of irradiated blood in patients.

Pharmacokinetics, urinary excretion and dosage regimen of diminazene in crossbred calves

The pharmacokinetics, urinary excretion and dosage regimen of diminazene were investigated in crossbred male calves following a single intramuscular dose (3.5 mg x kg-1). Following intramuscular administration, the pharmacokinetics of diminazene was described with a one-compartment open model. The absorption rate constant and absorption half-life were 9.86 +/- 3.06 h-1 and 0.121 +/- 0.40 h, respectively. The value of elimination half-life was 107.5 +/- 8.50 h. The apparent volume of distribution was 0.74 +/- 0.07 L x kg-1. Systemic availability following intramuscular administration was 91.7%. Approximately 65% of the administered dose of diminazene was eliminated in the urine within 24 h of its intramuscular administration. Diminazene was bound to plasma proteins to the extent of approximately 32%. The satisfactory intramuscular dosage regimen of diminazene for calves would be 2.24 mg x kg-1 followed by 1.5 mg x kg-1 at 7 days.

Pre-core mutant infections in the Canadian Inuit

BACKGROUND/AIMS

Previous cross-sectional data suggested that chronic hepatitis B viral (HBV) infections in the Canadian Inuit were inactive. The aim of this study was to confirm these findings and document the prevalence of the subsequently described "pre-core mutant" variant of HBV in this population.

METHODS

We obtained sera from residents of five remote Canadian Inuit communities. Residents were selected if they were known to be hepatitis B surface antigen (HBsAg) positive or had a history of liver disease. HBV serology, HBV-DNA, and pre-core mutant testing were performed by commercially available assays, polymerase chain reaction (PCR) and direct sequencing of the viral genome, respectively.

RESULTS

Sera were obtained from 176/266 (66%) of selected individuals. Thirty-eight (22%) were HBsAg positive and 16 (9.1%) anti-HBs positive. Of HBsAg positive carriers 25/38 (66%) were male as compared to 68/138 (49%) of the remaining individuals (p<0.05). Of 37 HBsAg positive carriers, none were HBeAg positive, 36 (97%) anti-HBe positive and one (3%) HBeAg and anti-HBe negative. Liver enzyme and function tests were normal in all cases. 30/37 (81%) HBsAg positive carriers were HBV-DNA positive and 26/30 (87%) were pre-core mutant positive.

CONCLUSION

The majority of HBV infections in community-based Canadian Inuit are inactive and the prevalence of pre-core mutant infections is the highest reported to date.

Transfusion safety in developing countries and the Indian scenario

The AIDS pandemic has brought into focus the importance of safe blood transfusion. The management of an effective transfusion service is an expensive endeavour even in the most developed countries, and is therefore a monumental challenge for developing countries with limited budgets and other priorities. HIV prevalence in the Indian population has shown a steady rise from 0.5% in 1990 to 1.2% in 1997 with the highest prevalence in cities. When the HIV infection was discovered in India in 1986, the health authorities set up the National AIDS Control Organisation (NACO) with a primary focus on ensuring a safe blood supply. NACO was funded by the World Bank and technically supported by WHO. The supreme Court of India has also taken up the issue of blood safety by banning paid donations by the end of 1997 and established the autonomous National Blood Transfusion Council and the State Transfusion Councils. The Drugs Controller of India and State F.D.A. have issued licences to all blood banks to streamline them after all requirements are met. However, there are a number of blood banks which are operating without licences. While India collects three million units of blood, barely 10% is available as blood components, and only a percentage of the blood is being screened for infectious markers. Nevertheless, there is a general recognition that an improved transfusion service is required in India.

Pharmacokinetics and dosage regimen of enrofloxacin in buffalo bulls after intramuscular administration

The disposition kinetics and dosage regimen of enrofloxacin were investigated in breeding buffalo bulls following a single intramuscular administration of 5 mg/kg. The absorption half-life, half-life of the terminal phase, apparent volume of distribution and total body clearance were 0.262+0.099 h, 1.97+/-0.23 h, 0.61+/-0.13 L/kg and 210.2+/-18.6 ml/(kg.h), respectively. Therapeutic plasma levels (> or = 1 microg/ml) were maintained for up to 6 h. A satisfactory intramuscular dosage regimen for enrofloxacin in buffalo bulls would be 8.5 mg/kg followed by 8.0 mg/kg at 8 h intervals.

Modification of the pharmacokinetics and dosage of cefuroxime by endotoxin-induced fever in buffalo calves

The effect of endotoxin-induced fever on the pharmacokinetics and dosage regimen of cefuroxime was investigated in buffalo calves following a single intravenous dose of 10 mg/kg body weight. The fever was induced by intravenous administration of E. coli endotoxin at a dose of 1 microg/kg body weight. The distribution and elimination half-lives were 0.100 h and 1.82 h, respectively, in healthy and 0.109 h and 2.28 h, respectively, in febrile buffalo calves. About 91% of the administered dose was excreted in the urine within 24 h. There was no effect of fever on the plasma protein binding of cefuroxime. The dosage regimen for intravenous administration of cefuroxime may be reduced in febrile conditions but the probability of this was only 0.3.

Red cell alloimmunization in multi-transfused chronic renal failure patients undergoing hemodialysis

Red blood cell (RBC) transfusions are frequently used in the management of patients with chronic renal failure (CRF) undergoing hemodialysis for dialysis-related anaemia. Consequently, they are subject to all hazards associated with repeated transfusions, such as red cell alloimmunization. A retrospective study was performed to estimate the frequency of alloimmunization against red cell antigens in multitransfused CRF patients. A total of 81 patients (67 males & 14 females) with CRF were studied who received a mean of 8.5 units of RBC matched for ABO & Rh(D) antigens only. Using standard techniques (indirect antiglobulin test, enzyme, polyethylene glycol, and low ionic strength solution), we observed a RBC alloimmunization rate of 9.8% (8/81). Nine alloantibodies were detected in 8 patients, and most (88%) involved antigens in the Rhesus & Kell systems. No correlation was observed with the alloantibody formation & number of units transfused. The calculated risk of 1.3% observed in the present study, suggests that renal failure patients are not at a higher risk of red cell alloimmunization than the general population.

Acquired hemolytic anemia after minor ABO incompatible renal transplantation

Passenger lymphocytes in grafted kidney have been reported to result in autoimmune hemolytic anemia (AIHA) in minor ABO incompatible transplants. We followed up 15 cases of minor ABO incompatible transplants for one year. Two patients developed severe but self-limited auto-immune hemolytic anemia within two weeks of renal transplantation. Both were blood group A and had received a kidney from a group O donor. Preoperative cross-match and antibody screen was negative; however subsequent to the hemolytic episode, group-specific blood was incompatible and patients were transfused with group O, cross-match compatible blood. Serological tests showed positive direct anti-globulin test (DAT) and anti-A was eluted from both cases.

Analysis of donor-deferral pattern in a voluntary blood donor population

A retrospective analysis of records of the deferred donors from 1 October 1992 to 31 December 1993 was performed. Of 14,269 prospective blood donors (13,030 males and 1,239 females), 2,431 (16.4%) donors were disqualified for various reasons: 8.1% of the donors were deferred for non-pathological causes while 91.9% were deferred for medical reasons. The most common cause for non-pathological deferral was volunteers attending below the minimum acceptable age (5.2%). Abnormal findings on physical examination accounted for 57.2% of the deferrals in which low body weight was the most common finding (32.3%) followed by low Hb (18.6%). A past history of jaundice was the leading cause for deferral on medical interview. Numerous prospective donors are currently being deferred based on empirically derived criteria. By developing strategies to identify and rationalize donor selection criteria, the blood transfusion services should be able to decrease unnecessary deferrals.

Subtyping of hepatitis C virus isolates by a line probe assay using hybridization

A reverse hybridization test (Inno-LiPA HCV; Innogenetics, N.V., Zwijnaarde, Belgium) was used for typing hepatitis C virus. All 38 samples, typed by PCR with primers from core and NS5 genes, were also genotyped by this test. Of the samples, 33 (87%) had the same subtypes by both assays. The correlations between PCR and Inno-LiPA for individual types were 77% for type I (1a), 90% for type II (1b), 100% for type III (2a), 100% for type IV (2b), and 100% for type V (3a). One of the type III (2a) samples also reacted with type I (1a) probes in the Inno-LiPA test.

Squamous cell carcinoma arising in Hashimoto's thyroiditis

The case of a 76-year-old white woman with squamous cell carcinoma of the thyroid gland arising in a background of Hashimoto's thyroiditis is presented. Squamous cell carcinoma of the thyroid gland is a very rare and aggressive tumor, and only a few cases are reported as arising in Hashimoto's thyroiditis. Although Hashimoto's thyroiditis alone does not necessarily predispose patients to malignancy, the finding of a prominent nodule in such a patient should suggest the possibility of malignancy, and an aggressive search and treatment regimen, including surgical intervention, should be pursued.

Performance of third-generation confirmatory tests for detection of antibody to hepatitis C virus

We investigated three immunoblot assays (RIBA 3.0 from Chiron, Matrix from Abbott Laboratories, and LiaTek III from Organon Teknika) for the detection of antibody to hepatitis C virus. RIBA 3.0 and Matrix require reactivity to two antigens and LiaTek III requires reactivity to one for a sample to be positive. We tested 80 samples that were positive in repeat enzyme immunoassays by supplemental tests. The results showed that 55, 46, and 28% were reactive by LiaTek III, RIBA 3.0, and Matrix, respectively; 54, 33, and 13% of the samples were indeterminate by Matrix, RIBA 3.0, and LiaTek III, respectively. There were 32, 21, and 16% nonreactive samples by LiaTek III, RIBA 3.0, and Matrix, respectively. Of the samples positive by RIBA 3.0, only 50 and 76% were reactive by Matrix and LiaTek III, respectively. A large number of samples that were indeterminate by RIBA 3.0 were positive by LiaTek III (52%). The core antigen was the most reactive antigen in all three tests (48 to 57%). The NS4 antigen in Matrix (20%) and LiaTek III (16%) was poorly reactive, although it performed better in RIBA 3.0 (45%). The NS5 and E2/NS1 antigens made minor contributions to reactivity. The combinations of the core, NS3, and NS4 antigens produced 77% of the RIBA 3.0 and 100% of the Matrix reactive samples. The results showed a poor correlation among the three tests.

Genotyping of Canadian hepatitis C virus isolates by PCR

We used PCR for hepatitis C virus (HCV) genotyping with type-specific primers from the core and NS5 genes. Type I was predominant in the general population (58% in blood donors) as well as in different risk groups, such as intravenous drug abusers (58%), blood transfusion recipients (64%), hemophiliacs (62%), and patients with HCV chronic liver disease (76%). Types II, III, and IV were less prevalent in Canada, being found in 10.92, 6.72, and 5.88% of the population, respectively. The type II core primer was not type specific and reacted with the majority of our type I HCV samples, suggesting a false-positive dual infection with two different genotypes (I and II). Digestion of these amplified type I and type II products with restriction endonuclease AccI proved to be very useful in the exclusion of false-positive dual type I and type II infections.

Detection of antibody to hepatitis C virus by second-generation enzyme immunoassay

Of 106 samples positive for antibody to hepatitis C virus (anti-HCV) by first-generation enzyme immunoassay (EIA-1), 63 (59%), 67 (63%) and 43 (41%) were reactive by second-generation EIAs (EIA-2). Among positive EIA-1 samples, 33% were reactive by second-generation recombinant immunoblot assay (RIBA-2). A higher percentage of positive EIA-2 samples, however, were reactive by RIBA-2. In the high-risk group there was a correlation between the EIA-2 and RIBA-2 results. In the low-risk group, however, the correlation was poor except in blood donors, in whom 57% of samples were reactive by EIA-2 and RIBA-2. Results showed that the sensitivity and specificity of EIA-2s has improved although further improvement is desirable.

Disposition kinetics, urinary excretion and dosage regimen of kanamycin in buffalo calves following single intravenous administration

The disposition kinetics and appropriate dosage regimen for kanamycin were investigated in buffalo calves following a single intravenous dose of 10 mg/kg body weight. The distribution and elimination half-lives were 0.12 +/- 0.01 h and 1.94 +/- 0.11 h, respectively. The apparent volume of distribution and total body clearance were 0.2 +/- 0.01 L/kg and 92.9 +/- 3.69 ml/kg/h, respectively. About 74% of the administered dose was excreted in urine in 24 h. A suitable dosage regimen for the intravenous administration of kanamycin was also calculated.

Detection of hepatitis C virus infection with recombinant immunoblot assay, synthetic immunoblot assay, and polymerase chain reaction

The newly developed immunoblot assay, RIBA SIA (recombinant and synthetic polypeptide immunoblot assay), Chiron, Calif., was compared with the commercially available second generation recombinant immunoblot assay (RIBA-2) for the detection of antibody to hepatitis C virus (anti-HCV). The two immunoblot tests were also compared with the polymerase chain reaction (PCR) for the detection of HCV RNA. Ninety-one percent of samples reactive by RIBA-2 were positive for anti-HCV by RIBA SIA. A total of 31% of RIBA-2 indeterminate samples became reactive by RIBA SIA, 24% became non-reactive, and 45% remained the same. Samples reactive by RIBA-2 or SIA from different risk groups, were mostly positive (67-100%) by PCR for HCV RNA. All indeterminate samples from hemophiliacs and intravenous drug users were PCR positive. RIBA SIA is more sensitive and specific than RIBA-2 and correlates well with PCR results.

Osteoradionecrosis of mandible in patients treated with definitive radiotherapy for carcinomas of oral cavity and oropharynx. A retrospective study

A retrospective analysis of 1140 cases of cancer of oral cavity and oropharynx treated with definitive radiotherapy was carried out with regard to the incidence and precipitating factors of mandibular osteoradionecrosis. 14 cases developed osteoradionecrosis out of which 10 had spontaneous mandibular necrosis and 4 had dental extractions in the area where osteoradionecrosis developed. Amongst the 10 cases of spontaneous osteoradionecrosis, 8 patients received doses of 6500 cGy in 6 1/2 weeks or 7000 cGy in 7 weeks by megavoltage cobalt 60 teletherapy and the remaining two patients received the doses of 6000 cGy in 6 weeks. The aforesaid 4 patients of osteoradionecrosis in the area of dental extractions had received doses of only 6000 cGy in 6 weeks.

Effect of ribavirin on hepatitis A virus replication in vitro

The effect of ribavirin on fetal Rhesus monkey kidney cells (FRhK-4) acutely or chronically infected with hepatitis A virus was studied. The effect of ribavirin on hepatitis A virus yield as detected by radioimmunoassay in acutely infected FRhK-4 cells was dependent on hepatitis A virus inoculum dose. Treatment with 100 μg/mL ribavirin completely inhibited hepatitis A virus growth in cultures infected with 100 to 800 tissue culture infectious dose 50 (TCID(50)) hepatitis A virus, but inocula of 800 to 1600 TCID(50) resulted in limited production of virus. The effect was time dependent and required more than 96 h of treatment to inhibit the virus completely. Ribavirin was less effective in treating cells persistently infected with hepatitis A virus, although there was significant inhibition of hepatitis A virus (82%) in persistently infected cells as well. Ribavirin had some inhibitory effect on cell growth; treatment with 25, 50 or 100 μg/mL ribavirin reduced cell growth by approximately 0, 20 and 40%, respectively.

Evaluation of hepatitis C virus kits

Hepatitis C virus (HCV) antibodies were detected in 85.9% of the samples by commercial enzyme immunoassay (EIA) kits. Most EIA-positive samples were reactive (80%) by the RIBA HCV test (Ortho Diagnostics). Samples with optical density values greater than or equal to 2.0 were mostly reactive (87%) by RIBA HCV test, in contrast to those with values less than or equal to 1.0 (6.6%). Samples which were indeterminate by the RIBA HCV test were positive (88.4%) by HCV neutralization EIA (Abbott Laboratories), along with 29.4% of samples which were nonreactive by the RIBA HCV test.

Evaluation of first- and second-generation RIBA kits for detection of antibody to hepatitis C virus

Samples reactive by first-generation recombinant immunoblot assay (RIBA) to detect antibody to hepatitis C virus (anti-HCV) (RIBA-1 [Chiron, Calif.]) remained reactive by a second-generation test (RIBA-2) for HCV antibodies. A total of 75% of specimens indeterminate by RIBA-1 became reactive, 12.5% were nonreactive, and 12.5% remained indeterminate by RIBA-2. Among RIBA-1-nonreactive specimens, 12.0% became positive and 5.1% became indeterminate by RIBA-2. The antigens c33c and c22-3 have increased the sensitivity of RIBA-2.

Kinetic study of the replication of a cell-culture-adapted hepatitis A virus

The kinetics of replication of hepatitis A virus (LCDC-01) was studied in foetal rhesus monkey kidney cells (FRhK-4). Cells infected at a multiplicity of infection (MOI) of 2.0 showed no viral antigen production until 12 h post-infection using radioimmuno assay (RIA); however, at 48 h post-infection a logarithmic increase in antigen concentration began, which peaked by day 7. Similar patterns were observed with cultures infected with lower MOI (0.20 and 0.02) but events were delayed by about 24 h. In contrast, detection of antigen by fluorescence antibody methods occurred at only 72 h after inoculation, with either 2.0 or 0.02 MOI, and peaked by day 9. The production of infectious virus did not begin until 24 h post-infection as measured by RIA and gradually peaked by day 6. Viral RNA was first detected 24 h post-infection by hybridization assay. The amount of viral RNA in the infected cells increased significantly between days 4 to 7. Restriction in the synthesis of RNA or infectious virus was not observed.

Disposition kinetics and dosage of cephaloridine in calves

The disposition kinetics and dosage regimen of cephaloridine were investigated in calves following a single intravenous dose of 10 mg.kg-1. The distribution half-life and elimination half-life were 0.16 +/- 0.02 and 1.96 +/- 0.16 h, respectively. The apparent volume of distribution was 0.64 +/- 0.06 l.kg-1 and total body clearance which represents the sum of all clearance processes, was 225.2 +/- 15.1 ml.kg-1.h-1. Based on kinetic parameters, a satisfactory intravenous dosage regimen of cephaloridine in calves would be 11.0 mg.kg-1 repeated every 8 h.

Alpha-fetoprotein in germ cell tumors. An immunohistochemical study

Total 40 cases of testicular and ovarian germ cell tumors and one case of extragonadal germ cell tumor were studied for the presence of alphafetoprotein (AFP) by indirect immunoperoxidase technique. All seminomas (7 cases) and teratomas (13 cases) were negative for AFP; while 85% of the pure embryonal carcinomas, (E.C.) all pure yolk sac tumors (Y.S.T.) (7 cases) and all embryonal carcinoma and yolk sac components in mixed tumors were AFP positive. Immunostaining of tumor marker appeared to help only in differentiating seminomatous and nonseminomatous tumors and hence does not provide any additional information for classification of these tumors.

Disposition and dosage regimen of cephaloridine in calves

The disposition and dosage regimen of cephaloridine were investigated in healthy calves following a single intramuscular administration of 10 mg/kg. The absorption halflife, elimination halflife, apparent volume of distribution and total body clearance were 0.107 +/- 0.025 h, 2.08 +/- 0.14 h, 0.70 +/- 0.07 L kg-1 and 235.8 +/- 21.9 ml kg-1 h-1, respectively. Therapeutic plasma levels (greater than or equal to 1 micrograms/ml) were maintained for up to 7 h. A satisfactory intramuscular dosage regimen for cephaloridine in calves would be 10 mg/kg repeated at 8 h intervals.

Subspecificity determination of HBsAg by radioimmunoassay

A radioimmunoassay method for subtyping hepatitus B surface antigen (HBsAg) was developed. Polystyrene beads pretreated with glutaraldehyde and coated with monospecific anti-d or anti-y antibodies were used. The treatment of beads with glutaraldehyde significantly increased the sensitivity of the test. Subtyping by radioimmunoassay was found to be more sensitive than by the immunodiffusion method. Fifty-nine percent of the samples tested could be subtyped by RIA and only 32% by immunodiffusion. The technique has the added advantage of utilising a commercially iodinated anti-HBs.