Primary gastric T-cell lymphoma of suppressor-cytotoxic (CD8+) phenotype: discordant expression of T-cell receptor subunit beta F1, CD7, and CD3 antigens.

Primary gastric T-cell lymphomas are rare neoplasms, and all but one of the previously phenotyped cases have shown a helper-inducer phenotype. The present case is the second reported case of a primary gastric T-cell lymphoma of suppressor-cytotoxic phenotype. The tumor histology was similar to that described in some forms of node-based peripheral T-cell lymphomas. Phenotypic analysis revealed low expression of pan-T marker CD7, reduced expression of CD3, but higher density and frequency of expression of CD8 antigens that could be predicted on the basis of the pan-T markers. Natural killer cell (NK) related markers CD16, HNK-1 and NKH-1 were not expressed by the neoplastic cells. T-cell receptor (TCR) beta subunit expression was detected on fewer cells than would have been predicted on the basis of CD3 and CD8 expression, and TCR delta chain expression was undetectable.     

Novel Semi‐Fluorinated Poly(ether imide)s Derived From 4‐(p‐Aminophenoxy)‐3‐trifluoromethyl‐4′‐aminobiphenyl

An unsymmetrical diamine monomer 4‐(p‐aminophenoxy)‐3‐trifluoromethyl‐4′‐aminobiphenyl has been synthesized successfully. This monomer leads to the synthesis of different novel poly(ether imide)s when reacted with different dianhydrides like pyromellatic dianhydride (PMDA), benzophenone tetracarboxylic acid dianhydride (BTDA), 2,2‐bis(3,4‐dicarboxyphenyl) hexafluoropropane (6FDA), and oxy diphthalic anhydride (ODA). The poly(ether imide) prepared from this monomer on reaction with 6FDA is soluble in several organic solvents such as N‐methylpyrolidinone (NMP), dimethylformamide (DMF), N,N‐dimethylacetamide (DMAc), tetrahydrofuran (THF), and CHCl₃. The poly(ether imide)s prepared from BTDA and ODA are soluble in NMP, DMF, and DMAc but not in THF or CHCl₃, whereas the polymer prepared from PMDA is soluble only in NMP. The water uptake value for these poly(ether imide) films is very low (0.2–0.5%), and exhibited low dielectric constants (2.81 at 1 MHz). The polymers exhibited high thermal stability up to 532 °C in air for 5% weight loss, and high glass transition temperatures up to 288 °C. The polymer exhibited high tensile strength up to 135 MPa, modulus 3.2 GPa, and elongation at break up to 25%, depending on the exact polymer structure.

The structure of the poly(ether imide) synthesised from 4‐(p‐aminophenoxy)‐3‐trifluoromethyl‐4′‐aminobiphenyl and 2,2‐bis(3,4‐dicarboxyphenyl) hexafluoropropane. This polymer was soluble in many organic solvents.     

Identification of MEN1 gene mutations in sporadic carcinoid tumors of the lung

Lung carcinoids occur sporadically and rarely in association with multiple endocrine neoplasia type 1 (MEN1). There are no well defined genetic abnormalities known to occur in these tumors. We studied 11 sporadic lung carcinoids for loss of heterozygosity (LOH) at the locus of the MEN1 gene on chromosome 11q13, and for mutations of the MEN1 gene using dideoxy fingerprinting. Additionally, a lung carcinoid from a MEN1 patient was studied. In four of 11 (36%) sporadic tumors, both copies of the MEN1 gene were inactivated. All four tumors showed the presence of a MEN1 gene mutation and loss of the other allele. Observed mutations included a 1 bp insertion, a 1 bp deletion, a 13 bp deletion and a single nucleotide substitution affecting a donor splice site. Each mutation predicts truncation or potentially complete loss of menin. The remaining seven tumors showed neither the presence of a MEN1 gene mutation nor 11q13 LOH. The tumor from the MEN1 patient showed LOH at chromosome 11q13 and a complex germline MEN1 gene mutation. The data implicate the MEN1 gene in the pathogenesis of sporadic lung carcinoids, representing the first defined genetic alteration in these tumors.      

Paramagnetic macrocyclic complexes as contrast agents for MR imaging: proton nuclear relaxation rate enhancement in aqueous solution and in rat tissues

Paramagnetic macrocyclic chelates show promise as magnetic resonance (MR) imaging contrast agents due to stability and relaxivity comparable to those of DTPA-type chelates. For the three copper and manganese macrocyclic complexes studied in aqueous solution, T1 and T2 relaxivities ranged from 0.14 to 5.88 mM-1sec-1 at 6.25 MHz. In rats, the intravenous administration of 16 mumol/kg of Mn(cyclam) caused the liver T1 relaxation rate to double at 15 minutes after injection. T1 measurements by pulsed MR imaging and manganese analyses on excised tissue showed that both relaxation rate (1/T1) and manganese content of liver and kidney increase linearly with the dosage of Mn(cyclam). The linear relationship between 1/T1 and manganese content can be considered an "in tissue" relaxivity plot for the agent. The resulting relaxivity is 54 mM-1sec-1 in liver, compared with 3.1 mM-1sec-1 in aqueous solution. Although this work is preliminary, the implication for medical MR imaging applications is that macrocyclic contrast agents can be effective at approximately one-tenth the current typical dose used for gadolinium DTPA.     

AIDS in obstetric practice

After a brief review of the AIDS virus, its transmission, and clinical aspects, the obstetric implications of HIV infections for a developing country like India are summarized. HIV, the virus that causes AIDS, is transmissible in utero with a 66% risk of infecting the fetus, and may cause intrauterine growth retardation or prematurity. HIV positive pregnant women may become immunosuppressed, so they should be offered pregnancy termination. A woman in labor infected with HIV should be managed like a woman with hepatitis B: intrauterine catheters, fetal scalp electrodes, and fetal blood sampling are contraindicated. Forceps and episiotomy should be used only if needed. Cesarean section to prevent intrapartum infection of the fetus is controversial. While breastfeeding is allowed, breast milk should not be donated to other infants. Nursing staff should be informed that HIV is much less transmissible than hepatitis.     

Phosphorus-Containing Fluoro-Sulfonated Polytriazole Membranes with High Proton Conductivity: Understanding Microstructural and Thermomechanical Behaviors as a Function of Degree of Sulfonation

The current article describes the design and synthesis of a new series of phosphorus-containing fluoro-sulfonated polytriazoles through click polymerization. The synthesized copolytriazoles (PTPFDSH-70 to 90) with different degrees of sulfonation (DS) from 70% to 90% are structurally interpreted by various spectroscopic techniques (¹H, ¹³C, and FTIR). The high molecular weight (weight average molecular weight as high as 77 500 g mol⁻¹ with polydispersity index of 2.29) polymers exhibits excellent mechanical (elongation at break up to 95%), thermal (10% decomposition temperature: 266–317 °C), and oxidative (>14.5 h) stability. The PTPFDSH-70 to 90 possess outstanding water-holding ability in hydrated conditions (swelling ratio [in-plane]: 6.2–7.3% at 80 °C). The microstructural alterations by their thermal relaxations and transitions with increasing DS in the polymers have been thoroughly investigated by dynamic mechanical analysis. The atomic force microscopy and transmission electron microscope images of the PTPFDSH-70 to 90 polymer membranes demonstrated the phase segregated interconnected ionic cluster-like morphology between hydrophilic and hydrophobic domains. The PTPFDSH-90 (DEB:PFAZ:DSAZ = 100:10:90) polymer membrane displays the proton conductivity (176 and 190 ms cm⁻¹ at 80 and 90 °C, respectively) higher than Nafion117 under similar test conditions.