Parathyroid carcinoma

INTRODUCTION

Parathyroid carcinoma is a rare tumor with an incidence of 0.5 to 4%. Preoperative differentiation from benign adenoma is very difficult. Several features, though nonspecific, have been used in differentiating parathyroid carcinoma from the adenoma.

MATERIAL AND METHOD

A retrospective analysis during the period of nine years, four cases of parathyroid carcinoma were diagnosed on the basis of per-operative local invasion and on histological evidence of capsular invasion and vascular invasion.

RESULT

We have different observations to make. Diagnosis of parathyroid carcinoma which was done on the basis of intra operative suspicion only. One patient died on 6th post operative day due to development of pancreatitis. At the follow-up of two years there was no local recurrence or distant metastasis.

CONCLUSION

It is preferable to have a high index of suspicion for parathyroid carcinoma when these features are present than to miss the opportunity for surgical cure by failing to consider it in the differential diagnosis.

Tandem plasmapheresis and hemodialysis

Many patients requiring plasmapheresis (PE) have renal failure and also need hemodialysis. If done separately almost 6-7 h is required. Hence, we decided to perform the procedures simultaneously in those patients requiring both PE and hemodialysis. The plasmafilter was inserted into the extracorporeal circuit after the hemodialyzer. A total of 8 such sessions of tandem PE and hemodialysis were performed in 2 patients. This is called tandem PE/hemodialysis. The total procedure was completed in the same time as is required for routine hemodialysis. The total amount of priming fluid is also less when PE and hemodialysis are performed separately. Thus, it is economically beneficial to the hospital and also convenient to the patient. Apart from transient episodes of hypotension, which were corrected by saline infusion, no other complications were noted.

Role of intracellular calcium in the spermicidal action of 2',4'-dichlorobenzamil, a novel contact spermicide

The Na+-Ca2+ exchanger and Ca2+-ATPase pumps reported to be present on the sperm membrane are responsible for maintaining the intracellular Ca2+ concentration that is involved in regulation of sperm function. We have investigated the role of intracellular Ca2+ in the presence of 2',4'-dichlorobenzamil hydrochloride (benzamil), a Na+-Ca2+ exchange inhibitor, on human sperm motility. The mechanism of the complementary spermicidal action produced by a combination of benzamil and propranolol on human spermatozoa has been investigated also. When administered alone benzamil and propranolol produced a dose- and time-dependent decrease in motility of sperm in ejaculated semen and spermatozoa separated from semen. A combination of benzamil and propranolol exhibited a complementary spermicidal action, thereby resulting in dose reduction of both drugs for obtaining total immotility within 1 min of administration. An increase in the intracellular Ca2+ level was found to contribute to the spermicidal activity. Inhibition of the Na+-Ca2+ exchange system on sperm membrane by benzamil and membrane stabilization by propranolol resulted in accumulation of Ca2+ inside the sperm cells. When the two drugs were used in combination the time required for the total loss of motility of spermatozoa was significantly reduced due to a similar mechanism of action of both drugs.

Realization of Bose-Einstein condensates in lower dimensions

Bose-Einstein condensates of sodium atoms have been prepared in optical and magnetic traps in which the energy-level spacing in one or two dimensions exceeds the interaction energy between atoms, realizing condensates of lower dimensionality. The crossover into two-dimensional and one-dimensional condensates was observed by a change in aspect ratio and by the release energy converging to a nonzero value when the number of trapped atoms was reduced.

Epidermal grafting for depigmentation due to discoid lupus erythematosus

BACKGROUND

Longstanding lesions of discoid lupus erythematosus (DLE) may heal with thin, depigmented scar(s). The depigmentation may fail to respond to medical therapies.

OBJECTIVE

To evaluate the efficacy of suction blister epidermal grafting in longstanding, quiescent, depigmented scar(s) of DLE.

METHODS

The suction blisters were raised on the lateral aspect of the upper third of the thigh in 4 patients (3 males, 1 female) with depigmented scars of DLE on the face. The roofs of the blisters were transferred to the dermabraded recipient area. Both donor and recipient sites were dressed with nonadherent tulle.

RESULTS

The dressings were removed after 7 days. The graft take was complete. The pigmentation achieved was more than 100% of the grafted area due to peripheral spread of the pigmentation and more than 75% of the depigmented area. The color match was good. There was no loss of pigment or recurrence/relapse of the disease during the follow-up of 6 months to 1 year.

CONCLUSIONS

Our preliminary results suggest that leukodermic scars of healed inactive DLE lesions can be successfully treated with epidermal grafting.

Phase 1 study of polyethylene glycol formulation of interferon alpha-2B (Schering 54031) in Philadelphia chromosome-positive chronic myelogenous leukemia

Interferon alpha (IFN-alpha) therapy improves prognosis in Philadelphia chromosome (Ph)-positive chronic myelogenous leukemia (CML). Polyethylene glycol (PEG) attached to IFN-alpha prolongs its half-life and may offer better therapy. The aims of this phase 1 study were to define the maximal tolerated dose (MTD), dose-limiting toxicities (DLTs), and response with PEG IFN-alpha-2b. Twenty-seven adults with Ph(+) CML in chronic or accelerated phases, in whom IFN-alpha treatment had failed, were studied. Patients had hematologic (9 patients) or cytogenetic resistance (12 patients) or intolerance to IFN-alpha (6 patients). PEG IFN-alpha-2b was given as a weekly subcutaneous injection starting at 0.75 microg/kg weekly and escalating to 1.5, 3, 4.5, 6, 7.5, and 9.0 microg/kg. The MTD was defined at 7.5 to 9 microg/kg; DLT included severe fatigue, neurotoxicity, liver function abnormalities, and myelosuppression. Longer administration of PEG IFN-alpha-2b resulted in chronic side effects not observed earlier, which defined the MTD and DLT. The proposed phase 2 dose of PEG IFN-alpha-2b was 6 microg/kg weekly. Among 19 patients with active disease, 7 (37%) achieved complete hematologic response (CHR); 2 (11%) had a cytogenetic response (complete). Among 8 patients treated in CHR, 7 (87%) improved cytogenetic response to complete (4 patients) or partial (3 patients). All 6 patients intolerant to IFN-alpha tolerated PEG IFN-alpha-2b; 4 improved their cytogenetic response. The results show that PEG IFN-alpha-2b is easier to deliver (once weekly), better tolerated, and perhaps more effective than IFN-alpha.

Use of pure t-butanol as a solvent for freeze-drying: a case study

1-(2-Chloroethyl)-3-sarcosinamide-1-nitrosourea, (SarCNU) (NSC-364432) is a new antitumor drug that is of interest to the National Cancer Institute. It is intended for use as an intravenous injection. Although SarCNU is sufficiently soluble in water to obtain the desired dosage, it is highly unstable. Its T(90) in aqueous solution at room temperature is less than 6 h. Neat tertiary butyl alcohol (TBA), a low toxicity, high vapor pressure and low melting solvent, was determined to be an excellent freeze-drying medium. Lyophilization of SarCNU from pure TBA produces a uniform cake composed of needle-shaped crystals. Thermal analysis and gas chromatography indicate that the cake contains less than 0.001% residual solvent. The SarCNU cake can be readily reconstituted with either water or an aqueous solution of 40% propylene glycol and 10% ethanol. The reconstituted solutions are stable for 4 and 13 h, respectively.

Conformational limitations of glycylsarcosine as a prototypic substrate for peptide transporters

Peptide transporters are present in all species to absorb the small peptides that occur ubiquitously as products of proteolysis. The broad substrate specificities of these systems allow them to be exploited therapeutically for delivery of peptidomimetic drugs in microbes and man. To this end, glycylsarcosine is currently used as a standard substrate for assaying peptidomimetic transport by peptide transporters. However, in this study we find it is unsuitable as a general substrate, based on assays of its transport by model bacterial peptide transporters and computer-based conformational analysis of its structure. Of the two generic transporters for di- and tripeptides, exemplified by Dpp and Tpp in Escherichia coli, only Dpp can transport glycylsarcosine. The explanation for this finding came from molecular modelling, which indicated that glycylsarcosine can adopt only a restricted range of conformers compared with typical dipeptides, and that of the conformers with a trans peptide bond, the majority have the specific psi and phi backbone torsion angles needed for molecular recognition and transport by Dpp but none possessed psi and phi torsions required for recognition by Tpp; moreover, 38% of its conformers have cis peptide bonds that are not substrates for any peptide transporter. Thus, using glycylsarcosine as substrate in competition assays with compounds that typically form conformers recognised by both types of peptide transporter will underestimate their transport. These findings have implications for assays of oral availability of peptidomimetic drugs such as beta-lactams, ACE inhibitors and anti-viral compounds, for which glycylsarcosine is routinely used.

Treating ingrown toenails by nail splinting with a flexible tube: an Indian experience

Ingrown toenail is a common problem, and currently available treatments are either quite invasive or associated with unacceptably high recurrence rate. Recently a new non-invasive therapy. "Nail splinting", has been introduced. In this procedure, the nail is splinted with a longitudinally incised plastic tube. We conducted the present study to evaluate the efficacy and safety of this procedure in fifty patients (68 nail edges in 61 nails) with ingrown toenails at all stages. The pain disappeared almost immediately, and inflammation subsided in about one week in all nail edges. Thirty-nine patients came for regular follow-up for six months after removal of the tube. Eight (20.5%) of these patients showed recurrence of the problem. No serious side effects were noted.

Role of phosphoinositide 3-kinase in the aggressive tumor growth of HT1080 human fibrosarcoma cells

We have developed a model system of human fibrosarcoma cell lines that do or do not possess and express an oncogenic mutant allele of N-ras. HT1080 cells contain an endogenous mutant allele of N-ras, whereas the derivative MCH603 cell line contains only wild-type N-ras. In an earlier study (S. Gupta et al., Mol. Cell. Biol. 20:9294-9306, 2000), we had shown that HT1080 cells produce rapidly growing, aggressive tumors in athymic nude mice, whereas MCH603 cells produced more slowly growing tumors and was termed weakly tumorigenic. An extensive analysis of the Ras signaling pathways (Raf, Rac1, and RhoA) provided evidence for a potential novel pathway that was critical for the aggressive tumorigenic phenotype and could be activated by elevated levels of constitutively active MEK. In this study we examined the role of phosphoinositide 3-kinase (PI 3-kinase) in the regulation of the transformed and aggressive tumorigenic phenotypes expressed in HT1080 cells. Both HT1080 (mutant N-ras) and MCH603 (wild-type N-ras) have similar levels of constitutively active Akt, a downstream target of activated PI 3-kinase. We find that both cell lines constitutively express platelet-derived growth factor (PDGF) and PDGF receptors. Transfection with tumor suppressor PTEN cDNA into HT1080 and constitutively active PI 3-kinase-CAAX cDNA into MCH603 cells, respectively, resulted in several interesting and novel observations. Activation of the PI 3-kinase/Akt pathway, including NF-kappaB, is not required for the aggressive tumorigenic phenotype in HT1080 cells. Activation of NF-kappaB is complex: in MCH603 cells it is mediated by Akt, whereas in HT1080 cells activation also involves other pathway(s) that are activated by mutant Ras. A threshold level of activation of PI 3-kinase is required in MCH603 cells before stimulatory cross talk to the RhoA, Rac1, and Raf pathways occurs, without a corresponding activation of Ras. The increased levels of activation seen were similar to those observed in HT1080 cells, except for Raf and MEK, which were more active than HT1080 levels. This cross talk results in conversion to the aggressive tumorigenic phenotype. This latter observation is consistent with our previous observation that overstimulation of the activity of endogenous members of Ras signaling pathways, activated MEK in particular, is a prerequisite for aggressive tumorigenic growth.

Cisapride improves gallbladder emptying in patients with type 2 diabetes mellitus

BACKGROUND AND AIMS

Gallbladder motor function is impaired in many patients with diabetes, and may be related to cholinergic nerve damage. Cisapride is a prokinetic drug of the gastrointestinal tract and acts by releasing acetylcholine from cholinergic nerve endings. The aim of this study was to determine the effect of cisapride on gallbladder emptying in patients with type 2 diabetes mellitus (DM).

METHODS

Gallbladder emptying and tests for autonomic neuropathy (AN) were performed in 27 patients with type 2 DM and in 10 healthy subjects. Gallbladder emptying was studied by using real-time ultrasonography after an overnight fast, and after the subjects received a breakfast that contained 2500 J. Gallbladder emptying was repeated after the treatment with cisapride (10 mg t.i.d.) for 1 week in all subjects.

RESULTS

Abnormal gallbladder emptying was present in 14 (51.9%) patients. The residual gallbladder volume (mean +/- SEM) was higher (9.3 +/- 1.0 vs 4.6 +/- 0.6; P = 0.002), and ejection fraction was lower (57.4 +/- 4.0 vs 74.2 +/- 2.4; P = 0.015) in diabetic patients than it was in healthy subjects. Cisapride produced a reduction in fasting and residual volumes (24.6 +/- 2.4 vs 20.0 +/- 1.4; P = 0.034 and 9.3 +/- 1.0 vs 5.9 +/- 1.1; P = 0.00003, respectively), and an improvement in ejection fraction (57.4 +/- 4.0 vs 72.6 +/- 3.8; P = 0.000007). The improvement in gallbladder emptying after cisapride therapy was confined to the patients with AN (n = 13) (57.3 +/- 5.4 vs 80.4 +/- 2.9; P = 0.0017), suggesting denervation supersensitivity with an upregulation of cholinergic receptors. There was no significant change in the ejection fraction in patients without AN (57.5 +/- 6.1 vs 65.4 +/- 6.5; P = NS). Sex, duration of diabetes, peripheral neuropathy, diabetic retinopathy and serum cholesterol level did not influence gallbladder emptying.

CONCLUSION

Impaired gallbladder emptying is common in patients with type 2 DM. Cisapride significantly improves gallbladder emptying in patients with autonomic neuropathy.

Pretargeting with amplification using polymeric peptide nucleic acid

One goal of this investigation was to develop a polymer conjugated with multiple copies of peptide nucleic acid (PNA) and with pharmacokinetic properties suitable for applications in vivo. The second goal was to establish whether the multiple copies of PNA on the polymer could be targeted by hybridization in vitro and in vivo with (99m)Tc-labeled complementary PNA (cPNA). If successful, this approach could then be considered in further investigations as an alternative to existing pretargeting approaches because of the potential for signal amplification in the target. A 80 KDa poly(methyl vinyl ether-alt-maleic acid) (PA) polymer was conjugated with multiple copies of PNA and with multiple copies of poly(ethylene glycol) (PEG) by reacting the NHS derivative of PA with the amine derivatives of PNA and PEG. Using (99m)Tc-MAG(3)-cPNA, targeting of PNA-PA-PEG was studied in vitro and in vivo in inflammation and tumor mouse models, in both cases relying upon nonspecific diffusion for localization. In addition, cPNA-avidin was considered as a clearing agent with biotinylated PNA-PA-PEG. About 80 PNAs could be conjugated to PA provided that about 200 PEGs were also conjugated to raise the aqueous solubility of the PNA-PA-PEG polymer lowered by the addition of the PNAs. About 70% of the PNAs on this polymer in vitro either in solution or attached to beads could be successfully targeted with (99m)Tc-cPNA. In both the inflammation and tumor mouse models, between 35 and 60% of these PNAs could be targeted in the lesions. The advantage of amplification was evident when less favorable results were obtained with PNA-PA-PEG conjugated with only six PNAs. We conclude that amplification can be achieved in vivo using polymers of PNA followed by radiolabeled complementary PNA and that the application of pretargeting using polymers of PNA for amplification can improve localization.

Deoxycholic acid (DCA) causes ligand-independent activation of epidermal growth factor receptor (EGFR) and FAS receptor in primary hepatocytes: inhibition of EGFR/mitogen-activated protein kinase-signaling module enhances DCA-induced apoptosis

Previous studies have argued that enhanced activity of the epidermal growth factor receptor (EGFR) and the mitogen-activated protein kinase (MAPK) pathway can promote tumor cell survival in response to cytotoxic insults. In this study, we examined the impact of MAPK signaling on the survival of primary hepatocytes exposed to low concentrations of deoxycholic acid (DCA, 50 microM). Treatment of hepatocytes with DCA caused MAPK activation, which was dependent upon ligand independent activation of EGFR, and downstream signaling through Ras and PI(3) kinase. Neither inhibition of MAPK signaling alone by MEK1/2 inhibitors, nor exposure to DCA alone, enhanced basal hepatocyte apoptosis, whereas inhibition of DCA-induced MAPK activation caused approximately 25% apoptosis within 6 h. Similar data were also obtained when either dominant negative EGFR-CD533 or dominant negative Ras N17 were used to block MAPK activation. DCA-induced apoptosis correlated with sequential cleavage of procaspase 8, BID, procaspase 9, and procaspase 3. Inhibition of MAPK potentiated bile acid-induced apoptosis in hepatocytes with mutant FAS-ligand, but did not enhance in hepatocytes that were null for FAS receptor expression. These data argues that DCA is causing ligand independent activation of the FAS receptor to stimulate an apoptotic response, which is counteracted by enhanced ligand-independent EGFR/MAPK signaling. In agreement with FAS-mediated cell killing, inhibition of caspase function with the use of dominant negative Fas-associated protein with death domain, a caspase 8 inhibitor (Ile-Glu-Thr-Asp-p-nitroanilide [IETD]) or dominant negative procaspase 8 blocked the potentiation of bile acid-induced apoptosis. Inhibition of bile acid-induced MAPK signaling enhanced the cleavage of BID and release of cytochrome c from mitochondria, which were all blocked by IETD. Despite activation of caspase 8, expression of dominant negative procaspase 9 blocked procaspase 3 cleavage and the potentiation of DCA-induced apoptosis. Treatment of hepatocytes with DCA transiently increased expression of the caspase 8 inhibitor proteins c-FLIP-(S) and c-FLIP-(L) that were reduced by inhibition of MAPK or PI(3) kinase. Constitutive overexpression of c-FLIP-(s) abolished the potentiation of bile acid-induced apoptosis. Collectively, our data argue that loss of DCA-induced EGFR/Ras/MAPK pathway function potentiates DCA-stimulated FAS-induced hepatocyte cell death via a reduction in the expression of c-FLIP isoforms.

Two cases of pseudoduplication of the external genitalia

In two newborn boys an accessory rudimentary phallus and scrotal sacs were present on the surface of a midline perineal swelling. Both boys had an associated high anorectal anomaly (ARA), a small phallus, and a bifid scrotum with absence of the scrotal raphé. One also had penile torsion with hypospadias and an accessory anal dimple. During definitive surgery for the ARA in one patient, excision of the perineal soft-tissue mass and overlying duplicated penoscrotal tissue was performed. The embryogenesis of this condition is discussed.

Inhibition of prostate carcinogenesis in TRAMP mice by oral infusion of green tea polyphenols

Development of effective chemopreventive agents against prostate cancer (CaP) for humans requires conclusive evidence of their efficacy in animal models that closely emulates human disease. The autochthonous transgenic adenocarcinoma of the mouse prostate (TRAMP) model, which spontaneously develops metastatic CaP, is one such model that mimics progressive forms of human disease. Employing male TRAMP mice, we show that oral infusion of a polyphenolic fraction isolated from green tea (GTP) at a human achievable dose (equivalent to six cups of green tea per day) significantly inhibits CaP development and increases survival in these mice. In two separate experiments, the cumulative incidence of palpable tumors at 32 weeks of age in 20 untreated mice was 100% (20 of 20). In these mice, 95% (19 of 20), 65% (13 of 20), 40% (8 of 20), and 25% (5 of 20) of the animals exhibited distant site metastases to lymph nodes, lungs, liver, and bone, respectively. However, 0.1% GTP (wt/vol) provided as the sole source of drinking fluid to TRAMP mice from 8 to 32 weeks of age resulted in (i) significant delay in primary tumor incidence and tumor burden as assessed sequentially by MRI, (ii) significant decrease in prostate (64%) and genitourinary (GU) (72%) weight, (iii) significant inhibition in serum insulin-like growth factor-I and restoration of insulin-like growth factor binding protein-3 levels, and (iv) marked reduction in the protein expression of proliferating cell nuclear antigen (PCNA) in the prostate compared with water-fed TRAMP mice. The striking observation of this study was that GTP infusion resulted in almost complete inhibition of distant site metastases. Furthermore, GTP consumption caused significant apoptosis of CaP cells, which possibly resulted in reduced dissemination of cancer cells, thereby causing inhibition of prostate cancer development, progression, and metastasis of CaP to distant organ sites.

Attitudes to menopause and hormone replacement therapy among Asian and Caucasian women general practitioners

OBJECTIVE

To look for any differences in attitudes to menopause and hormone replacement therapy (HRT) between Asian and Caucasian women standardised for educational background, socio-economic status and access to medical information.

METHOD

Self administered postal questionnaire sent to 144 women doctors (general practitioners) in defined geographical areas.

RESULTS

The overall response rate was 61%. Both Asian and Caucasian women responded in a similar manner for most aspects. A high proportion of these women doctors (over 75%) would seek HRT at the climacteric. More Asian respondents reported a fear of breast cancer (P=0.001), and that a woman feels less of a woman after the menopause (P=0.02). More Caucasian respondents felt positively about the potential for HRT to enhance enjoyment of life (P=0.01).

CONCLUSIONS

The lack of major differences between the ethnic groups in our sample suggests that variations reported elsewhere may be due to lack of knowledge and/or differences in socio-economic status.

Observation of vortex phase singularities in Bose-Einstein condensates

We have observed phase singularities due to vortex excitation in Bose-Einstein condensates. Vortices were created by moving a laser beam through a condensate. They were observed as dislocations in the interference fringes formed by the stirred condensate and a second unperturbed condensate. The velocity dependence for vortex excitation and the time scale for re-establishing a uniform phase across the condensate were determined.

Direct observation of release of cytochrome c from lipid-encapsulated protein by peroxide and superoxide: a possible mechanism for drug-induced apoptosis

Release of cytochrome c from inside lipid vesicles and from inside proteoliposomes formed by cytochrome c oxidase has been studied by spectrophotometric methods. The protein encapsulated inside vesicles did not form complex with sodium azide solution added externally. Both hydrogen peroxide and superoxide were found to cause release of cytochrome c from the lipid encapsulated protein, which was detected from the distinct spectral changes due to the formation of the azide complex of cytochrome c in the solution. Cytochrome c encapsulated inside proteoliposomes containing cytochrome c oxidase (CcO) did not release the cytochrome c during enzymatic turnover of CcO. The anticancer drug, doxorubicin, was found to inhibit the biochemical function of cytochrome c oxidase and release of cytochrome c was observed from the proteoliposome encapsulating the protein during the enzymatic turnover in the presence of doxorubicin. The results indicated that the inhibition of enzymatic activity by doxorubicin possibly leads to the formation of reactive oxygen species, which induce the release of cytochrome c from inside to outside of the membrane.