Inhalation exposures to acrylamide in biomedical laboratories

This study evaluated airborne acrylamide exposures experienced by laboratory personnel using either crystalline or commercially available solutions of acrylamide to make polyacrylamide gels. Exposures were monitored for a short-term (15-min) sampling period, during the weighing of the crystalline acrylamide or the removal of the acrylamide solution from its original container, and a long-term period, during which a sample was collected for as long as the subject was potentially exposed to acrylamide. Mean air concentrations for the 15-min exposures were 7.20 +/- 5.64 micrograms/m3 and 5.81 +/- 4.53 micrograms/m3 for the users of crystalline and solution acrylamide, respectively, although this difference was not statistically significant (p > 0.05). Mean concentrations for the long-term exposures were 12.77 +/- 24.20 micrograms/m3 for workers employing crystalline acrylamide and 4.22 +/- 7.05 micrograms/m3 for personnel using acrylamide solutions. This difference was also not statistically significant. Although the results indicate that the research laboratory personnel were generally exposed to measurable concentrations of acrylamide, with several subjects exposed to elevated levels, the calculated 8-hour time-weighted average exposures were below current occupational exposure limits. However, because the neurotoxic effects of acrylamide are cumulative and it is a suspected carcinogen, all exposures should be kept as low as reasonably achievable.     

Contribution of ionotropic glutamate receptors and voltage-dependent calcium channels to the potentiation phenomenon induced by transient pentylenetetrazol in the CA1 region of rat hippocampal slices

The role of ionotropic glutamate receptors and voltage-dependent calcium channels (VDCCs) in potentiation phenomenon and epileptic activity induced by a transient pentylenetetrazol (PTZ) application in the CA1 region of rat hippocampal slices was investigated. Also we examined whether adenosine as an inhibitory neuromodulator would interact with expression of the long-lasting effect of transient PTZ. Population spikes (PS) were recorded in the CA1 cell body layer of the hippocampal slices following stratum radiatum stimulation. Changes in the PS amplitude potentiation and number of extra PS, which induced by transient PTZ were used as indices to quantify the effects of drugs. PS input-output curve was significantly increased 10 min after PTZ application and persisted at least for 60 min after PTZ washout. Polyspikes also appeared, but did not persist. Both ketamine and APV reduced the extent of potentiation of PS amplitude but had no effect on number of extra PS. The selective non-NMDA receptor antagonist CNQX prevented the amplitude potentiation and the generation of extra PS. The blocker of VDCCs, verapamil, prevented the amplitude potentiation and inhibited polyspike activity. Co-application of adenosine and PTZ produced a rapid and reversible decrease in the PS amplitude, but PTZ-induced potentiation phenomenon was observed after washout. It is concluded that ionotropic glutamate receptors as well as VDCCs involve in the PTZ-induced LTP of PS amplitude. PTZ-induced LTP is also insensitive to adenosine. The epileptiform activity induced by a transient PTZ application could be attributed to VDCCs. The polyspikes mediated by VDCCs are dependent on prior activation of AMPA receptors.     

Laser-induced fluorescence spectroscopy for in vivo diagnosis of non-melanoma skin cancers

BACKGROUND AND OBJECTIVES: Laser-induced fluorescence spectroscopy is a non-invasive technique previously used for detection of cancer in a variety of organ systems. The objective of this study was to determine whether in vivo laser-induced fluorescence spectroscopy alone at the visible excitation wavelength of 410 nm could be used to detect non-melanoma skin cancers. STUDY DESIGN/MATERIALS AND METHODS: The system consisted of a nitrogen/dye laser tuned at 410 nm, an optical multichannel analyzer, and a fiber optic probe for excitation of tissue and collection of fluorescence emission. Two hundred and seventy nine measurements were performed from normal and abnormal tissues in 49 patients. Patients were classified as having either skin types I, II, or III. Biopsy of the abnormal tissues were then performed. Each measurement was assigned as either normal, basal cell carcinoma (BCC), squamous cell carcinoma (SCC), pre-cancerous, or benign. Total emission photon count was used as the discriminating index. A threshold value was calculated to separate normal tissue indices from indices of cancer tissues. The classification accuracy of each data point was determined using the threshold value. RESULTS: Cancers were classified 93, 89, and 78% correctly in patients with skin types I, II, and III, respectively. Normal tissues were classified 93, 88, and 50% correctly in patients with skin types I, II, and III, respectively. Using the same threshold, pre-cancerous spectra were classified 78 and 100% correctly in skin types I and III, respectively. Benign lesions were classified 100, 46, and 27% correctly in patient with skin types I, II, and III, respectively. CONCLUSIONS: In vivo laser induced fluorescence spectroscopy at 410 nm excitation and using the intensity of emission signal is effective for detection of BCC, SCC, and actinic keratosis, specially in patients with light colored skin.     

Effect of transient hippocampal inhibition on amygdaloid kindled seizures and amygdaloid kindling rate

In this study the effect of transient inhibition of the CA1 region of the dorsal hippocampus by lidocaine on amygdala kindling rate and amygdaloid kindled seizures was investigated. In experiment 1, rats were divided into four groups. In group 1, animals were implanted only with a tripolar electrode into the amygdala but in groups 2-4, two guide cannulae were also implanted into the CA1 regions of the dorsal hippocampi. Animals were stimulated daily to be kindled. In groups 3 and 4, saline or 2% lidocaine (1 microl/2 min) was also injected respectively into the hippocampus, 5 min before each stimulation. Results obtained showed that amygdala kindling rate and the number of stimulations to receive from stage 4 to stage 5 seizure were significantly increased in group 4. In experiment 2, lidocaine (1% and 2%) was infused (1 microl/2 min) into the hippocampus of amygdala kindled rats bilaterally and animals were stimulated at 5, 15 and 30 min after drug injection. Twenty four h before lidocaine injection, saline was also infused (1 microl/2 min) into the hippocampus as control. Obtained results showed that afterdischarge duration was reduced 5 min after lidocaine (1% and 2%) injection. Stage 5 seizure duration was also decreased 5 and 15 min after 2% lidocaine. Thus, it may be suggested that in amygdala kindling, activation of the hippocampal CA1 region has a role in seizure acquisition and seizure severity so that inhibition of this region results in decreasing of seizure severity and retards amygdala kindling rate.     

Laparoscopic Ligation of Uterine Vasculature for Fertility-Sparing Management of Postabortal Hemorrhage

Study Objective

To present a surgical video in which bilateral uterine vasculature was ligated laparoscopically in order to preserve the uterus in a patient with postabortal hemorrhage.

Thyroid biological evaluation: critical study

Laboratory tests to assess thyroid gland function have changed considerably over the past few years, with the development of techniques allowing for the direct routine determination of unbound thyroid hormones (tri and tetra-iodothyronine), the "ultra-sensitive" assay of serum concentrations of TSH (thyroid-stimulating hormone) and finally, the radioimmunological assay of anti TSH-receptor antibodies. In our study, which excluded patients having an excess of iodine or who had serious disease of an organ other than the thyroid, we assessed the impact of these parameters respectively on various disease categories. An innovation has been made in that anti TSH-receptor antibody assay is now possible in everyday practice while up to the present this was only possible in the hospital setting and with a limited number of cases: this titer is important as a classification parameter in diagnosing Grave's disease and has prognostic importance to monitor treatment of patients suffering from this disorder. The "ultrasensitive" version of measuring thyrotropic hormone requires a new strategy: TSH assessment becomes the first-line diagnosis test to evaluate thyroid function because it differentiates from control subjects, as well as patients with hyper ou hypothyroidism who are not receiving therapy. In other cases, dosing of the free hormones T3 and T4 remains a vital supplementary test.     

The study of the influence of prolactin on gonadal steroids metabolism by the human chorionic gonadotropin test. Plasma and urinary determinations in 27 subjects (control, hyperprolactinemic, normoprolactinemic but hypogonadic subjects) (author's transl)

In order to determine whether hyperprolactinemia besides its action at the hypothalamic level, acts at the gonadal level, a serie of 28 stimulations by Human Chorionic Gonadotropin (HCG : 5 000 IU X 3) is reported. The following parameters were measured in plasma and in urine before and during 4 consecutive days following the injection of HCG : Progesterone (P), 17 OH Progestérone (17 OHP), Androstenedione (A), Testostérone (T), Dihydrotesterone (DHT), Estrone (E1), 17 beta estradiol (E2), Urinary Androstanediol (Adiol) Testosterone Glucuronide (G.T.) and phenolsteroids (PS). The test was performed in both sex, in 3 different groups including normal, hyperprolactinemic and normoprolactinemic but hypogonadic subjects (hypopituitarism). These data suggest that in hyperprolactinemic subjects: there is no steroid 5 alpha reductase abnormality in male patients, and there is no gonadal resistance to HCG stimulation in both sex, at least to the high doses of HCG used in this study.     

Noscapine suppresses angiotensin converting enzyme inhibitors-induced cough

BACKGROUND: Dry cough is a common side-effect of the angiotensin converting enzyme inhibitors (ACEI) and is a major limiting factor of their use. It has been suggested that ACEI cause this side-effect by potentiation of the bradykinin effect. Previous work in our laboratory has shown that noscapine, an antitussive drug, inhibits the effect of bradykinin. METHODS: To investigate the effect of noscapine on ACEI-induced cough, 611 hypertensive patients who were being treated with ACEI were evaluated for the incidence of persistent dry cough. RESULTS: A cough had developed in 65 (10.6%) patients, two (3.1%) of whom also had severe respiratory distress that required hospitalisation and immediate discontinuation of the ACEI. Forty-two (64.6%) patients had developed a mild cough and 21 (32.3%) patients had developed a moderate to severe cough. The patients with moderate to severe cough received 15 mg of noscapine, orally three times daily, while they continued ACEI. Noscapine effectively resolved the cough in 19 (90%) patients within 4-9 days of starting treatment. CONCLUSION: Noscapine, possibly by inhibition of bradykinin synthesis, eliminates ACEI-induced cough in the majority of patients and allows them to continue with ACEI therapy.