Sexual arousal and the quality of semen produced by masturbation

A new stable isotope dilution gas chromatograph-mass spectrometric method of analysis of homogentisic acid is described. Using this method, homogentisic acid is measured for the first time in normal human plasma. The assay of sera from nine normal individuals yielded a range of values from 2.4 to 12 ng/ml. The method appears to be very sensitive and may be useful in the characterization of heterozygotes for alkaptonuria and other disorders of tyrosine degradation.     

Swedish gynecologists'' and general practitioners'' views on the climacteric period: knowledge, attitudes and management strategies

The cytolytic T lymphocyte (CTL) response has often been used to assess the reconstitution of T cell function after allogeneic or autologous bone marrow transplantation (BMT). Less is known, however, about the reconstitution of the CTL response after peripheral blood stem cell transplantation (PBSCT). Therefore, we investigated the CTL response against Epstein-Barr virus (EBV) of patients undergoing autologous PBSCT. CTLs of six patients with relapsed non-Hodgkin's lymphoma and multiple myeloma were established before and at different times after PBSCT by in vitro stimulation of peripheral blood lymphocytes with autologous EBV-transformed lymphoblastoid cell lines (LCLs). The efficiency of T cell priming by LCLs was assessed at the time of initiation of CTL lines; the proliferative response was strongly reduced during the first 4 months and increased 5 months or more following PBSCT. Cytolytic activity was measured after three or four restimulations of CTLs. All patients investigated had a detectable EBV-specific CTL response which was poor during the first weeks after transplantation, accompanied by a strong non-MHC-restricted cytotoxic activity and a high proportion of CD56-positive T cells. Five or more months after PBSCT, a specific CTL response against EBV was seen which was similar to the situation prior to PBSCT, while the unspecific cytotoxic response decreased. Blocking experiments with monoclonal anti-CD3, anti-CD8 or anti-MHC I antibodies resulted in substantial inhibition of autologous LCL lysis, whereas anti-CD4 or anti-MHC II antibodies had no effect. Finally, autologous PHA blasts of a patient with the HLA haplotype A1/9+, B5/8+, Cw4/7+, were loaded with various EBNA-derived nonapeptides known to be presented by HLA B8 or A11, and exposed to autologous, EBV-directed CTLs. Specific lysis by CTLs only occurred with HLA B8-, but not with HLA A11-restricted nonapeptides. This demonstrated the existence of an MHC I-restricted anti-EBV CTL response after PBSCT. Taken together, the results show that the anlaysis of the EBV-directed CTL activity may serve as a surrogate marker to assess the reconstitution of the cellular immune response in patients undergoing autologous PBSCT.     

Alkalinization of lidocaine does not hasten the onset of axillary brachial plexus block

We assessed the onset of sensory and motor blockade as well as the distribution of sensory blockade after axillary brachial plexus block with 1.5% lidocaine hydrochloride 1:200,000 epinephrine with and without sodium bicarbonate in 38 patients. The onset of analgesia and anesthesia was recorded over the distributions of the median, ulnar, radial, and medial cutaneous nerves of the forearm, medial cutaneous and lateral cutaneous nerves of the arm, and musculocutaneous nerve. The onset of motor blockade of elbow and wrist movements was also recorded. Data were analyzed by using survival techniques and compared by using log rank tests. Only the onset of analgesia in the medial cutaneous nerves of the arm and forearm, and the onset of anesthesia in the medial cutaneous nerve of the arm were significantly faster (P < 0.05) with alkalinization of lidocaine. Our study showed that alkalinization of lidocaine does not significantly hasten block onset in most terminal nerve distributions. IMPLICATIONS: We examined whether alkalinizing a local anesthetic would quicken the onset of a regional upper limb nerve blockade. We found that alkalinization of lidocaine did not offer a significant clinical advantage in axillary brachial plexus blockade.     

Induction of diplochromosomes in mammalian cells by inhibitors of topoisomerase II

Diplochromosomes, consisting of four chromatids lying side-by-side, instead of the normal two, are produced when cells go through two rounds of DNA replication without separation of chromatids. They are thus an indication of the failure of the normal chromosome separation mechanism. In the present experiments, induction of diplochromosomes by inhibitors of topoisomerase II (Topo II) was used to provide further evidence that Topo II is required for separation of daughter chromosomes. Actively growing cultures of CHO cells were treated with Colcemid, and separated into metaphase and interphase fractions, each of which was treated for 2 h with the Topo II inhibitor being tested. The cells were then cultivated in fresh medium without inhibitor for periods of between 18 and 44 h, and metaphase cells once again accumulated by treatment with Colcemid. Chromosome preparations were made in the standard way and stained with Giemsa. Up to 2,000 metaphases were counted from each culture, and the proportion with diplochromosomes calculated. At appropriate concentrations, the Topo II inhibitors etoposide and mitoxantrone induced substantial levels of metaphases with diplochromosomes in cultures that had been treated when the cells were in interphase (up to 30% and 11%, respectively). Amsacrine, however, only produced a smaller proportion (4.7%) of metaphases with diplochromosomes after a much longer culture period following treatment. All the inhibitors caused severe chromosome damage. When used to treat metaphase cells, mitoxantrone and amsacrine only induced diplochromosomes after prolonged culture, although a small number of diplochromosomes were seen after etoposide treatment and a shorter period of culture. Results with cells treated in metaphase might indicate that Topo II is, in fact, not required for anaphase chromosome separation, although it is clearly important for segregation of newly replicated DNA.     

Use of metabolically competent human hepatoma cells for the detection of mutagens and antimutagens

The human hepatoma line (Hep G2) has retained the activities of various phase I and phase II enzymes which play a crucial role in the activation/detoxification of genotoxic procarcinogens and reflect the metabolism of such compounds in vivo better than experimental models with metabolically incompetent cells and exogenous activation mixtures. In the last years, methodologies have been developed which enable the detection of genotoxic effects in Hep G2 cells. Appropriate endpoints are the induction of 6-TGr mutants, of micronuclei and of comets (single cell gel electrophoresis assay). It has been demonstrated that various classes of environmental carcinogens such as nitrosamines, aflatoxins, aromatic and heterocyclic amines and polycyclic aromatic hydrocarbons can be detected in genotoxicity assays with Hep G2 cells. Furthermore, it has been shown that these assays can distinguish between structurally related carcinogens and non-carcinogens, and positive results have been obtained with rodent carcinogens (such as safrole and hexamethylphosphoramide) which give false negative results in conventional in vitro assays with rat liver homogenates. Hep G2 cells have also been used in antimutagenicity studies and can identify mechanisms not detected in conventional in vitro systems such as induction of detoxifying enzymes, inactivation of endogenously formed DNA-reactive metabolites and intracellular inhibition of activating enzymes.     

Detection of CYP1A1 protein in human liver and induction by TCDD in precision-cut liver slices incubated in dynamic organ culture

Cytochrome P4501A1 (CYP1A1) has been implicated in the conversion of numerous polycyclic aromatic hydrocarbons into electrophilic species capable of binding covalently to DNA and has therefore been postulated to be involved in the initiation of carcinogenesis. The expression of CYP1A1 protein appears not to be constitutive, but is readily inducible by aryl hydrocarbon (Ah) receptor ligands in a majority of tissues of experimental animals, especially the liver. To date, there is conflicting evidence for the expression or inducibility of CYP1A1 protein in human liver. In this present study, we report the detection of CYP1A1 in all 20 human liver microsomal samples tested by standard western immunoblotting with chemiluminescent detection using a specific monoclonal antibody (mAb 1-12-3) directed against a marine fish (scup) cytochrome P450E. mAb 1-12-3 has been shown previously to specifically recognize CYP1A1 in mammals. This system consistently demonstrated a detection sensitivity as low as 0.01-0.025 pmol CYP1A1 per lane. In the samples where CYP1A1 protein levels were quantitated, CYP1A1 ranged from approximately 0.4 to 5 pmol CYP1A1/mg microsomal protein. Additionally, the inducibility of CYP1A1 protein was demonstrated by incubating precision-cut human liver slices in dynamic organ culture for up to 96 h in the presence of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). The specificity of mAb 1-12-3 was tested using several purified human and rat cytochrome P450s to ensure that the protein being detected was CYP1A1. mAb 1-12-3 did not cross-react with human CYP1A2 or CYP3A4 or rat CYP1B1, but did strongly recognize CYP1A1. However, there was a very weak cross-reactivity of mAb 1-12-3 with human CYP2E1, approximately 75-fold less compared with CYP1A1. In order to confirm CYP1A1 as the immunoreactive protein detected in human liver, microsomal samples were subjected to two-dimensional electrophoresis involving isoelectric focusing followed by SDS-PAGE and immunoblotting. Utilizing mAb 1-12-3, the human liver microsomal samples displayed an immunoblotting profile matching that obtained from a microsomal preparation from a AHH-1 TK+/- cell line expressing solely human CYP1A1 and differing from the profile obtained using a polyclonal antibody directed against CYP2E1 and cells expressing CYP2E1. Furthermore, mAb 1-12-3 recognized only one protein of identical mobility on the two-dimensional blots from human liver microsomes and AHH-1 TK+/- cells expressing CYP1A1, while displaying no reaction to cells expressing only CYP2E1. In conclusion, CYP1A1 appears to be expressed in human liver at low levels and is inducible upon exposure to TCDD.     

Neurologic evaluation of the upper extremity

Symptoms and disease processes can overlap, and neurologic symptoms of the hand or arm are not necessarily due to local pathology. To combat these difficulties, the authors present a basic review of neuroanatomy, the neurologic examination, the principles of electromyography, and the process of formulation.     

Transmission disequilibrium analysis of a triplet repeat within the hKCa3 gene using family trios with schizophrenia

We evaluated the long-term outcome of farmer's lung (FL) patients and matched control farmers using high-resolution computed tomography (HRCT). The study population consisted of 88 FL patients and 83 control farmers, matched by age, sex, and smoking habits. The mean time after the first diagnosed episode of FL was 14 yr. The great majority, 82%, of the studied subjects were nonsmokers. Clinical studies included HRCT, spirometry, and pulmonary diffusing capacity. Emphysema was found significantly more often (23%) in FL patients than in control farmers (7%) (p = 0.006). The presence of emphysema was 18% in nonsmoking and 44% in smoking FL patients, the respective values being 4% and 20% in control farmers. Patients with recurrent attacks of FL tended to have emphysema more often (p = 0. 08) than patients who had experienced only a single attack. Fibrosis was observed in 17% of the FL patients and in 10% of the control farmers (p = 0.2). Miliary changes were found in 12% of the FL patients compared with 4% of the control farmers (p = 0.07). Both emphysematous and fibrotic but not miliary changes correlated significantly with impaired pulmonary function. In conclusion, farmer's lung disease seems to be associated with an increased risk of developing emphysema.     

Three novel SRY mutations in XY gonadal dysgenesis and the enigma of XY gonadal dysgenesis cases without SRY mutations

Mutations in the Y-located testis-determining gene SRY are one cause for XY sex reversal. We have previously identified four SRY mutations in a total of 45 sex-reversed females with XY gonadal dysgenesis (XY GD). In a new sample of 16 XY GD cases, three previously undescribed SRY mutations were identified. Two are point mutations that lead to amino acid substitutions in the HMG domain of SRY, M64R, and F67V. The third SRY mutation is a single base insertion 5' to the HMG box within codon 43, converting this lysine codon to a stop codon (K43X). A total of 33 SRY mutations have so far been described that account for only 10-15% of XY GD females. A further 10-15% of these cases result from deletion of SRY due to aberrant X/Y interchange. The etiology of the remaining 70-80% of XY GD cases is still enigmatic. Possible explanations for these XY sex-reversal cases are discussed.