A validated stable isotope dilution liquid chromatography tandem mass spectrometry assay for the trace analysis of cocaine and its major metabolites in plasma

A validated method has been developed for the simultaneous quantitation of cocaine and its major metabolites (ecgonine methyl ester, benzoylecgonine, and norcocaine) in rat plasma. The method is based upon the use of stable isotope dilution liquid chromatography/atmospheric pressure chemical ionization/tandem mass spectrometry. Previously reported methods do not have the sensitivity and specificity that can be attained with this method. Plasma samples required no cleanup apart from protein precipitation, and no derivatization was required. Selected reaction monitoring was performed on the transitions of m/z 200 to m/z 182 (ecgonine methyl ester), m/z 290 to m/z 168 (benzoylecgonine), m/z 304 to m/z 182 (cocaine), and m/z 290 to m/z 168 (norcocaine). The standard curves were linear over the range from 2 ng/mL (benzoylecgonine, cocaine, and norcocaine) or 5 ng/mL (ecgonine methyl ester) to 1000 ng/mL in rat plasma. The lower limit of quantitation (LLQ) for benzoylecgonine, cocaine, and norcocaine was 2 ng/mL, and for ecgonine methyl ester, the LLQ was 5 ng/mL for plasma. This simple, rapid, reliable, and sensitive method of quantitation had excellent accuracy and precision for the four analytes. The method was sensitive enough to permit a detailed study of the pharmacokinetics of cocaine and its metabolites after administration of a bolus intravenous dose to rats.

Cyclophosphamide modulates gene expression in neonatal rat testis following antenatal exposure to fetuses during testicular differentiation

The present study was designed to evaluate the altered gene expression in neonatal rat testis after antenatal exposure of cyclophosphamide (one time single dose of either 2, 10, or 20 mg/kg body weight) to the developing fetuses, especially at the time of male sex differentiation. The rationale behind these experiments is to know about the involvement of Y-chromosome gene-dependent product(s) associated with gonadal dysfunction. Using SDS-polyacrylamide gel electrophoresis and photosensitive silver staining technique, the study shows that the variety of proteins of different molecular weight ranges 40,000 to 127,000 Da are modulated by cyclophosphamide exposure to the developing testis. Interestingly, the overexpression of one protein of 74,500 Da was observed both in supernatant as well as in pallet fractions. The qualitative and quantitative regulation of newly synthesized protein appearance or disappearance is observed in a dose-dependent manner.

Cysticercus immunoblot assay in patients with single, small enhancing lesions and multilesional neurocysticercosis

A single, small (< 20 mm), ring or disc shaped contrast enhancing lesion located at the cortical-subcortical junction with minimal or no surrounding edema on computed tomography is the commonest mode of presentation of neurocysticercosis in the Indian subcontinent. Serum samples of 37 patients with these single, small enhancing lesions (SSEL's) and five patients with typical multilesional parenchymal neurocysticercosis were tested by the electro-immunoblot transfer (EITB) assay and the enzyme linked immunosorbent assay (ELISA). EITB was positive in 18 patients (48.64%) and ELISA was positive in 21 patients (56.76%) with SSEL's. On the other hand EITB was positive in all five patients (100%) and ELISA was positive in four patients (80%) with multilesional neurocysticercosis. The low sensitivity of the EITB in the SSEL's is probably linked to an insufficient immune stimulation provided by a single cysticercus cyst.

Local recurrence and survival among black women with early-stage breast cancer treated with breast-conservation therapy or mastectomy

BACKGROUND

Black women with breast cancer have significantly worse survival rates and receive diagnoses at relatively younger ages, compared with white patients with breast cancer, in the United States. Young age at diagnosis has been associated with increased risk for local recurrence (LR) after breast-conservation therapy (BCT). The goal of this study was to evaluate the impact of age and BCT on LR and survival rates among black patients with breast cancer.

METHODS

The records for 363 black women treated for breast cancer (excluding stage IV disease) at a comprehensive cancer center were reviewed.

RESULTS

Fifty-eight percent of patients (n = 211) had tumors < or = 5 cm in diameter. Forty-two of these patients (19.9%) received BCT; the LR rate for this group was 9.8%. A total of 168 patients (79.6%) underwent mastectomy; the LR rate for this group was 8.9%. Data on the primary operation were unavailable for one patient. Five-year disease-free survival rates were similar for patients treated with BCT and those treated with mastectomy (88% and 73%, respectively). LR was associated with significant decreases in 5-year overall survival rates for both the BCT group (67% vs. 95%, P < .01) and the mastectomy group (43% vs. 76%, P < .01). LR and 5-year disease-specific survival rates were similar for patients <50 years of age and patients > or = 50 years of age, regardless of treatment.

CONCLUSIONS

LR and survival rates are not compromised by the use of BCT among black American patients. LR is associated with an increased risk of breast cancer death, regardless of treatment type. Younger age at diagnosis was not associated with an increased rate of LR after BCT in this series.

Epidemiology of NSAID induced gastrointestinal complications

Nonsteroidal antiinflammatory drugs (NSAID) are one of the most commonly used classes of medications worldwide. It is estimated that more than 30 million people take NSAID daily. Gastrointestinal (GI) complications related to NSAID therapy are the most prevalent category of adverse drug reactions. Patients with arthritis are among the most frequent users of NSAID and are therefore particularly at risk for these side effects. To evaluate the nature of NSAID-related GI complications and to determine how their frequency can be reduced, a series of studies of such complications in patients with rheumatic disease have been carried out based on data from the Arthritis, Rheumatism, and Aging Medical Information System (ARAMIS). This report briefly reviews the literature and presents recent findings from the ARAMIS studies, which provide an update on published information. It addresses whether GI side effects such as dyspepsia can serve as warning symptoms for life-threatening GI complications and describes the risk factors for these events. It also summarizes a study that investigated whether H2-receptor antagonists and antacids affect the development of serious GI complications. In addition, ongoing research and topics to be addressed in future studies are described.

In vivo resistance to photofrin-mediated photodynamic therapy in radiation-induced fibrosarcoma cells resistant to in vitro Photofrin-mediated photodynamic therapy

The effects of Photofrin-mediated photodynamic therapy (PDT) on the in vitro cell survival and in vivo tumor growth of murine radiation-induced fibrosarcoma (RIF) cell tumors have been examined following in vivo PDT treatment of tumors. The response to in vivo PDT is examined in tumors derived from RIF-1 mouse fibrosarcoma cells and in tumors derived from RIF-8A cells, which show in vitro resistance to PDT. A significant reduction in tumor volume is observed over the first three days following in vivo PDT treatment of either 5 or 10 mg/ kg. The reduction in tumor volume is greater for a 10 compared to a 5 mg/ml dose and occurs to a similar extent for both RIF-1 and RIF-8A tumors. The re-growth is significantly delayed for RIF-1 compared to RIF-8A tumors, indicating a greater response for RIF-1 tumors compared to RIF-8A tumors following PDT. A reduced response of the RIF-8A compared to the RIF-1 tumor cells is also observed in the clonogenic survival of cells from tumors that were excised and explanted in vitro immediately following in vivo PDT treatment. These data indicate that the intrinsic cell sensitivity to PDT is an important component in the mechanism that leads to tumor response following in vivo photodynamic therapy.

Comparison of the effectiveness of adenovirus vectors expressing cyclin kinase inhibitors p16INK4A, p18INK4C, p19INK4D, p21(WAF1/CIP1) and p27KIP1 in inducing cell cycle arrest, apoptosis and inhibition of tumorigenicity

Cell cycle regulatory proteins are important candidates for therapeutic tumour suppressors. Adenovirus vectors were constructed to overexpress cyclin kinase inhibitors p16INK4A, p18INK4C, p19INK4D, p21(WAF1/CIP1) and p27KIP1 under the control of the murine cytomegalovirus immediate early gene promoter. These vectors directed the efficient expression of each of the cyclin kinase inhibitors and induced growth arrest, inhibited DNA synthesis, and prevented phosphorylation of the retinoblastoma protein (pRb) in cell lines expressing functional pRb. In pRb-deficient cells, expression of the cyclin kinase inhibitors was not effective in inhibiting DNA replication or growth arrest. Interestingly, three of the cyclin kinase inhibitors, p16, p18 and p27 were found to induce apoptotic death in transduced HeLa and A549 cells. When the vectors were tested for their ability to inhibit tumorigenicity in a polyomavirus middle T antigen model of murine breast carcinoma, expression of the cyclin kinase inhibitors resulted in a delay in tumour formation that varied from several weeks for the p19 expressing vector to greater than 25 weeks for the p27 expressing vector. When tumours were injected directly with the adenovirus vectors expressing the cyclin kinase inhibitors, only treatment with the vector expressing p16 resulted in a delay in tumour growth.

Mitochondrial membrane potential regulation is independent of c-fos expression

Tumour cells contain mitochondria with elevated membrane potentials compared with normal cells, and thus this feature provides a selective target for destroying tumour cells. To improve mitochondrial-based therapies, a better understanding of the factors involved in regulating mitochondria are required. Since v-fos overexpression has been shown to elevate mitochondrial membrane potentials in rat fibroblasts, we investigated whether the human homologue, c-fos, was also capable of regulating the mitochondrial membrane potential in cells. Rat fibroblasts transfected with the c-fos gene did not accumulate more rhodamine 123 (Rh123) nor did they retain this Rh123 for extended periods of time compared with their parental line. Moreover, there was no difference in survival following dequalinium chloride (Deca) treatment between transfectants and controls. Similarly, reduction of c-fos expression in rat fibroblasts did not significantly alter their mitochondrial membrane potential. In addition, human ovarian carcinoma cells, which overexpress the c-fos gene, did not accumulate more Rh123 nor were they hypersensitive to Deca compared with their parental line. In another human ovarian carcinoma cell line, selection of variants with lower mitochondrial membrane potential did not alter c-fos mRNA or protein levels. These data suggest that alterations in c-fos expression do not regulate the magnitude of the mitochondrial membrane potential.

Reappearing CT lesions: 4 cases

An overwhelming majority of disappearing CT lesions in India have been aetiologically linked to cysticercosis. We report 4 patients with disappearing CT lesions in whom the lesion later reappeared at the same (3 patients) or different site (1 patient). One patient was a Taenia carrier. Serial MRI evaluation in one patient revealed a persisting lesion in the interval period. The contribution of these observations towards the understanding of the aetiology of disappearing CT lesions is discussed.

New observations on carrying angle

Based on experiments on fresh cadaveric and accidentally amputated 8 upper limbs of children, study of ulnae for presence and absence of non articular strip on the trochlear notch, measurements of carrying angle, length of forearm bones, pronation-supination, height and weight in 2250 infants, children and adults of various age groups and clinical observations on 800 cases of injuries around elbow many new facts have been observed about the development of the carrying angle and its significance in the etiopathogenesis of various types of fractures seen around the elbow. The carrying angle develops in response to pronation of the forearm and is dependent on length of the forearm bones. Lesser the length of forearm bones greater is the carrying angle. So the carrying angle is more in shorter persons as compared to taller persons. It is abduction at the shoulder and not the carrying angle which keeps the swinging upper limbs away from the side of the pelvis during walking. Carrying angle is not a secondary sex character. The type of fracture a child sustains after fall on outstretched hand is also determined by the value of the carrying angle. A new type of fracture hitherto undescribed in the literature, T-Y fracture of the distal humeral epiphysis is also reported.

Alveolar adenoma: a histochemical, immunohistochemical, and ultrastructural analysis of 17 cases

Alveolar adenoma of lung is a rare benign neoplasm of uncertain histogenesis. Its rarity hampers characterization of its epithelial and mesenchymal elements. Clinical and histopathologic features of 17 alveolar adenomas were reviewed. Histochemistry was performed on 10 cases, ultrastructural analysis on two, and immunohistochemistry on six cases for pneumocyte markers, thyroid transcription factor (TTF-1), surfactant protein markers pro-SP-B and pro-SP-C, and the Clara cell marker, CC10. Immunohistochemistry was performed in nine cases for desmin, smooth muscle actin, muscle-specific actin, cytokeratin, proliferating cell nuclear antigen (PCNA), factor VIII, and carcinoembryonic antigen. The mean age was 53 years. Seven cases occurred in men, and nine occurred in women. The age and sex were not known for one patient. The tumors were coin lesions on chest radiographs in asymptomatic patients except for one (cough). The mean size was 2.2 cm. The tumors were well demarcated with multiple cystic spaces containing granular material. Mostly type 2 pneumocytes lined the cystic spaces with fewer type 1 cells and no Clara cells. This was confirmed by staining for TTF-1, pro-SP-B, and pro-SP-C and by ultrastructure. CC10 was negative in all cases. The stroma varied from prominent spindle cells with a myxoid matrix to thin alveolar septa. The interstitial spindle cells resembled fibroblasts by immunohistochemistry and ultrastructure. Follow-up data available in five cases showed no recurrence at 2, 2, 5, 8, and 13 years. In summary, alveolar adenoma is a benign neoplasm consisting of an intimate admixture of alveolar epithelial and septal mesenchymal tissue. Most of the epithelial cells are type 2 pneumocytes, and the interstitial stromal cells are fibroblasts or fibroblast-like cells. Recognition of its characteristic morphological appearance allows for its distinction from other benign lesions of the lung.

Clinical course of breast cancer patients with complete pathologic primary tumor and axillary lymph node response to doxorubicin-based neoadjuvant chemotherapy

PURPOSE

To assess patient and tumor characteristics associated with a complete pathologic response (pCR) in both the breast and axillary lymph node specimens and the outcome of patients found to have a pCR after neoadjuvant chemotherapy for locally advanced breast cancer (LABC).

PATIENTS AND METHODS

Three hundred seventy-two LABC patients received treatment in two prospective neoadjuvant trials using four cycles of doxorubicin-containing chemotherapy. Patients had a total mastectomy with axillary dissection or segmental mastectomy and axillary dissection followed by four or more cycles of additional chemotherapy. Patients then received irradiation treatment of the chest-wall or breast and regional lymphatics. Median follow-up was 58 months (range, 8 to 99 months).

RESULTS

The initial nodal status, age, and stage distribution of patients with a pCR were not significantly different from those of patients with less than a pCR (P>.05). Patients with a pCR had initial tumors that were more likely to be estrogen receptor (ER)-negative (P<.01), and anaplastic (P = .01) but of smaller size (P<.01) than those of patients with less than a pCR. Upon multivariate analysis, the effects of ER status and nuclear grade were independent of initial tumor size. Sixteen percent of the patients in this study (n = 60) had a pathologic complete primary tumor response. Twelve percent of patients (n = 43) had no microscopic evidence of invasive cancer in their breast and axillary specimens. A pathologic complete primary tumor response was predictive of a complete axillary lymph node response (P<.01 ). The 5-year overall and disease-free survival rates were significantly higher in the group who had a pCR (89% and 87%, respectively) than in the group who had less than a pCR (64% and 58%, respectively; P<.01).

CONCLUSION

Neoadjuvant chemotherapy has the capacity to completely clear the breast and axillary lymph nodes of invasive tumor before surgery. Patients with LABC who have a pCR in the breast and axillary nodes have a significantly improved disease-free survival rate. However, a pCR does not entirely eliminate recurrence. Further efforts should focus on elucidating the molecular mechanisms associated with this response.

Transforming growth factor beta1 acts as an inducer of matrix metalloproteinase expression and activity in human bone-metastasizing cancer cells

Bone metastases are a common complication in prostate and breast cancer patients. It leads to extensive morbidity and eventually mortality. Matrix metalloproteinases (MMPs) are known to be involved in the metastatic process. MMP activity can be down-regulated by transforming growth factor beta1 (TGF-beta1), a growth-modulating factor, found in high concentrations in the bone. TGF-beta1 acts through the TGF-beta1 inhibitory element (TIE) element, a cis-acting element found in the promoter region of most MMP genes, with the exception of MMP-2. We used three human cell lines relevant for bone metastases, namely prostate adenocarcinoma PC-3, breast adenocarcinoma MDA-MB-231, and adenocarcinoma cells of unknown origin, Hs696, and one human osteosarcoma cell line, SAOS-2, and showed that in these cell lines TGF-beta1 partially lost its repressing action on MMP expression. TGF-beta1 was able to induce MMP-9 activity and protein expression in all three bone-metastatic tumour cell types, whereas MMP-9 protein levels were repressed in SAOS-2 cells. In PC-3 cells, TGF-beta1 repressed MMP-1 expression, whereas in MDA-MB-231 and SAOS-2 cells, an increase in the expression of MMP-1 protein was detected. Additionally, an increase in MMP-3 expression was observed in Hs696 cells. Expression and activity of the tissue inhibitors of matrix metalloproteinases, TIMP-1 and TIMP-2, were found increased in both PC-3 and MDA-MB-231 cells. With respect to cell proliferation, TGF-beta1 was able to induce a dose-dependent growth inhibition of up to 50% in primary human mammary epithelial cells. However, in none of the tumour cell lines was TGF-beta1 able to suppress growth substantially. Data presented in this paper support the hypothesis that TGF-beta1 can potentially disrupt the balance existing between osteoclast- and osteoblast-derived MMP activity by inducing altered expression of matrix metalloproteinases and their tissue inhibitors derived from bone-metastasizing cancer cells. This could eventually lead to skeletal destruction in patients with advanced metastatic disease.

Role of polypeptides in the treatment and diagnosis of osteoporosis

Osteoporosis is a common disorder characterized by reduced bone mineral density, deterioration of the microarchitecture of bone tissue and increased risk of fracture. The aim of treatment of osteoporosis is to maintain and, ideally, to restore bone strength safely. In recent years the role of polypeptide growth factors in bone metabolism has begun to appear. It has been proposed that alterations in the expression or production of growth factor can modulate the proliferation and activity of bone forming cells. In this direction, the role of structurally diverse peptides for the management and diagnosis of osteoporosis has attracted the attention of many investigators. This paper reviews numerous findings concerning the use of polypeptides, hormones, and growth factors, for the management of osteoporosis. Many of the compounds mentioned here are experimental prototypes of new therapeutic classes. Though it is unlikely that some of the compounds may ever be used clinically, development of safe and efficacious agents in each class will define the future course of therapy for osteoporosis.

A review of the readmissions of patients with tetraplegia to the Regional Spinal Injuries Centre, Southport, United Kingdom, between January 1994 and December 1995

Patients with chronic tetraplegia are prone to develop unique clinical problems which require readmission to specialised centres where the health professionals are trained specifically to diagnose, and treat the diseases afflicting this group of patients. An appraisal of the readmission pattern of tetraplegic patients will provide the necessary data for planning allocation of beds for treatment of chronic tetraplegic patients. Hospital records of patients with tetraplegia readmitted to the Regional Spinal Injuries Centre, Southport, UK between 1 January 1994 and 31 December 1995 were analyzed to find out the number of tetraplegic patients who required readmission, reasons for readmission, duration of hospital stay, and mortality among patients readmitted. During the 2-year period, 155 tetraplegic patients were readmitted and 44 of them (28.4%) required more than one readmission (total readmission episodes: 221); these patients occupied 4.5 beds which is equivalent to 11.5% of the total bed capacity of the spinal unit. Among the reasons for the readmissions, evaluation and care of urinary tract disorders topped the list with 96 readmission episodes (43.43%) involving 70 patients; the median hospital stay was 3 days, and 18 patients (26%) required more than one readmission during this period. One hospital bed was occupied by the tetraplegic patients requiring treatment/evaluation of urinary tract disorders. Assessment and treatment of cardio-respiratory diseases was the second most common reason for readmission with 51 readmission episodes pertaining to 27 patients having a median hospital stay of 6 days; 13 patients (48%) were readmitted more than once within this 2-year period. Treatment of cardio-respiratory diseases in chronic tetraplegic patients required 1.2 hospital beds yearly. Only five tetraplegic patients were readmitted for treatment of pressure sore(s); however they had a prolonged hospital stay (median duration: 101 days). Social reasons accounted for 13 readmission episodes concerning nine patients who stayed in the hospital for varying periods (median: 6.5 days; mean: 35 days). Four tetraplegic patients readmitted with acute chest infection expired. An 81 year-old tetraplegic died of myocardial infarction. Urinary sepsis, renal insufficiency, respiratory failure and intra-cerebral haemorrhage accounted for the demise of a 41 year-old tetraplegic patient following surgical removal of a large, impacted stone at the pelviureteric junction. A tetraplegic patient who was admitted with haematuria subsequently underwent cystectomy for squamous cell carcinoma of the urinary bladder; he developed secondaries and expired 5 months later. As more patients with high cervical spinal cord injury survive the initial period of trauma, and as the life expectancy of tetraplegic patients increases, it is likely that greater numbers of tetraplegic patients will be requiring readmission to spinal injuries centre. Although it may be possible to prevent some of the complications of spinal cord injury and hence the need for a readmission, progress in medicine and rehabilitation technology will create additional demands for readmissions of chronic tetraplegic patients in order to implement the newer therapeutic strategies. Thus a change in the pattern of readmission of chronic tetraplegic patients is likely to be the future trend and this should be taken into account while making plans for providing the optimum care to chronic tetraplegic patients.

Homocysteine-dependent alterations in mitochondrial gene expression, function and structure. Homocysteine and H2O2 act synergistically to enhance mitochondrial damage

Mitochondrial abnormalities have been identified in hepatocytes of patients with hyperhomocysteinemia and in endothelial cells from the aortas of rats with diet-induced hyperhomocysteinemia. However, the mechanism by which homocysteine affects mitochondria is unknown. In this report, homocysteine-induced expression of the mitochondrial electron transport chain gene, cytochrome c oxidase III/ATPase 6,8 (CO3/ATPase 6,8), was identified in a human megakaryocytic cell line DAMI using mRNA differential display. Steady-state mRNA levels of CO3/ATPase 6,8, as well as other mitochondrial transcripts, were increased in DAMI cells by homocysteine in a concentration- and time-dependent manner. Despite an increase in mitochondrial RNA levels and changes in mitochondrial ultrastructure, no effect on either cell growth or mitochondrial respiration rates was observed in DAMI cells exposed to homocysteine at concentrations up to 1 mM. In contrast, 1 mM homocysteine in the presence of Cu2+, which is known to generate H2O2, significantly decreased mitochondrial RNA levels, caused gross morphological changes in mitochondrial ultrastructure, and inhibited both cell growth and mitochondrial respiration rates. However, precursors of cellular glutathione and preexposure to heat shock blocked the decrease in mitochondrial RNA levels caused by homocysteine and Cu2+. The observations that (i) homocysteine and H2O2, but not H2O2 alone, caused a decrease in mitochondrial RNA levels, (ii) intracellular levels of H2O2 were significantly increased in the presence of homocysteine and Cu2+, and (iii) catalase, but not free radical scavengers, prevented a decrease in mitochondrial RNA levels, provide evidence that homocysteine and H2O2 act synergistically to cause mitochondrial damage. Furthermore, our findings suggest that intracellular glutathione and heat shock proteins play a role in protecting mitochondria against the adverse effects elicited by homocysteine and H2O2.

Anatomical basis for inferior alveolar nerve block

This article discusses a scientific approach to customize the inferior alveolar nerve block technique, by focusing on individual anatomy and neurophysiology.

Cloning of the mating type loci from Pyrenopeziza brassicae reveals the presence of a novel mating type gene within a discomycete MAT 1-2 locus encoding a putative metallothionein-like protein

The mating type loci were cloned from Pyrenopeziza brassicae by chromosome walking from a mating type-linked polymerase chain reaction (PCR) fragment and shown to be idiomorphic by sequence analysis. The MAT 1-1 locus is approximately 3.2 kb and contains a single gene encoding a putative high-mobility group (HMG) domain protein. The MAT 1-2 locus is approximately 3.9 kb with three open reading frames (ORFs) encoding a putative HMG domain, an alpha-1 domain and metallothionein-like proteins. The putative alpha-1 domain ORF on MAT 1-2 is transcribed in the opposite orientation to the other two transcripts and extends into non-idiomorphic sequence. This is the first report of sequence analysis of the mating type loci from a discomycete fungus, which has revealed an interesting mating type infrastructure within the MAT 1-2 locus. Although metallothionein-like proteins have been implicated in a number of processes in animals and plants, they have not to date been implicated in the mating process of filamentous fungi. Possible roles for metallothionein-like proteins in the mating process are discussed.