The surface morphology of the avian tectorial membrane

The structure of the tectorial membrane of the chick was evaluated by scanning electron microscopy (SEM), using standard techniques, and, for the first time, by studying unfixed tectorial membranes with video-enhanced light microscopy techniques (AVEC-DIC). The SEM pictures show a widely varying morphology, ranging from a fully perforated tectorial membrane to a completely closed upper boundary, with a smooth surface. Based on several indicators, it is concluded that the latter presents the more natural state. This was confirmed by the results of the AVEC-DIC technique, which show a highly homogeneous structure. In contrast to the bulk of the tectorial membrane, its lower surface shows discrete structures, especially regularly oriented fibril bundles.     

Taurine in pediatric nutrition: review and update

Taurine was long considered an end product of the metabolism of the sulfur-containing amino acids, methionine and cyst(e)ine. Its only clearly recognized biochemical role had been as a substrate in the conjugation of bile acids. Taurine is found free in millimolar concentrations in animal tissues, particularly those that are excitable, rich in membranes, and generate oxidants. Various lines of evidence suggest one major nutritional role as protecting cell membranes by attenuating toxic substances and/or by acting as an osmoregulator. The totality of evidence suggests that taurine is nonessential in the rodent, it is an essential amino acid in the cat, and it is conditionally essential in man and monkey. Absence from the diet of a conditionally essential nutrient does not produce immediate deficiency disease but, in the long term, can cause problems. Taurine is now added to many infant formulas as a measure of prudence to provide improved nourishment with the same margin of safety for its newly identified physiologic functions as that found in human milk. Such supplementation can be justified by the finding of improved fat absorption in preterm infants and in children with cystic fibrosis, as well as by salutary effects on auditory brainstem-evoked responses in preterm infants. Experimental findings in animal models and in human cell models provide further justification for taurine supplementation of infant formulas.     

123I-amphetamine-SPECT in classical migraine and migraine accompagnée

Migraine is considered to be a functional neurological disorder. In classical migraine (headache associated with prodromal visual field disturbances) and migraine accompagnée (headache associated with transient neurological symptoms), disturbances of cerebral blood flow and amine metabolism are thought to be pathogenetic factors. However, conventional methods of neuroimaging (CAT, NMR) usually do not yield any pathological findings in patients. Since 123I-iodoamphetamine (123I-IMP) crosses the intact blood brain barrier, 123I-IMP-SPECT is used for the assessment of cerebral perfusion in various neurological diseases, including functional disorders. 123I-IMP-SPECT was performed on 5 patients with classical migraine and 18 patients with migraine accompagnée. At the time of investigation, all patients were symptom-free. Cerebral blood flow was decreased in all patients with migraine accompagnée, and often corresponded to the site of headache as well as to the topography of transient neurological symptoms. This reduction was most obvious in a patient with persisting neurological symptoms. Most patients with classical migraine, however, did not show any alteration of cerebral perfusion. It appears that migraine--and in particular migraine accompagnée--is characterized by a permanent alteration not only of cerebral blood flow but also of neuronal activity. Migraine attacks may occur in connection with exacerbations of preexisting metabolic alterations.     

Benzodiazepine ([3H]flunitrazepam) binding in cat visual cortex: ontogenesis of normal characteristics and the effects of dark rearing

[3H]Flunitrazepam (FNZ) binding sites were characterized in homogenates of cat visual cortex during normal postnatal development and following dark rearing from birth. In parallel experiments, the distribution and density of [3H]FNZ binding sites were examined by in vitro autoradiographic or 'scrape' methods. In homogenates, Bmax measurements showed low early values, rising to a peak in receptor density at about 60 days postnatal, followed by a decline in adulthood. At all ages, gamma-aminobutyric acid (GABA) altered the Kd, but not the Bmax of [3H]FNZ binding sites. Kd values showed a general increase with age, parallelled by an increased sensitivity to GABA. Receptor autoradiography revealed that the highest density of [3H]FNZ binding sites was in layer IV of cats of all ages. Deafferentation of extrinsic inputs to the visual cortex by surgical undercutting did not alter this pattern of laminar distribution, indicating that the receptors were associated with intrinsic cortical elements rather than subcortical inputs. Dark rearing had no effect on [3H]FNZ laminar distribution in the visual cortex. The Bmax was higher at 30 days postnatal, but did not differ significantly thereafter. Modulation by GABA was concomitantly higher at 30 days, but lower than normal in dark-reared animals at ages greater than 30 days postnatal. The results are discussed in relation to the normal and abnormal development of GABA receptors in the cat visual cortex.     

Myeloid regeneration after bone-marrow transplantation monitored by serum measurements of myeloperoxidase, lysozyme and lactoferrin

Bone-marrow regeneration after chemo- and radiotherapy-induced aplasia can be monitored by serum levels of myeloperoxidase (MPO), lysozyme (LYS) and lactoferrin (LF). In 10 patients with leukemia, serum measurements were performed before and after bone-marrow transplantation. Bone-marrow regeneration was suggested by increments in serum MPO and LYS 5 and 4 days prior to the increase in mononuclear cells (Mono) and 10 and 9 d before the increase in polymorphonuclear leukocytes (PMN) in the peripheral blood. LF started to rise 4.5 d before detectable circulating PMNs. 2 patients with early relapses of leukemia post transplantation are shown to display atypical patterns of serum MPO and LYS. We conclude that serum measurements of MPO, LYS and LF may be used as early and sensitive means to monitor bone-marrow activity during hematological regeneration. However, the findings also strongly support the earlier proposal that MPO alone may be used to reflect myeloid activity in the bone-marrow in general.     

Phase II study of iproplatin in metastatic breast carcinoma

Thirty patients with progressive metastatic breast cancer and one prior chemotherapy regimen were treated with iproplatin at a starting dose of 300 mg/m2 iv every 3 weeks. After the first 11 patients, the starting dose was decreased to 270 mg/m2. There were one complete remission, three partial remissions, and two minor responses. Responses were observed in soft tissue and osseous and visceral areas. Grade 3 nausea and vomiting were observed in 38% of patients, and grade 3 diarrhea occurred in 31%. The dose-limiting toxicity was thrombocytopenia, which required dose de-escalation in 15 patients. No nephrotoxicity, neurotoxicity, or ototoxicity was observed. Iproplatin has modest antitumor activity in this group of previously treated patients with metastatic breast cancer.     

Fate of TR-2, the hepatic metabolite of the tremorgenic mycotoxin verruculogen, in sheep

1. Verruculogen is eliminated in bile after transformation to TR-2, only a trace of which was excreted as such in faeces of sheep given verruculogen per os. Negligible TR-2 was present free in urine; no glucuronide was found. 2. An isomer of TR-2, a minor component of the bile of sheep given verruculogen, has been defined by 1H-n.m.r. spectroscopy and the isomerism involves the disposition of the two adjacent hydroxyl groups with a concomitant change in the conformation of the ring adjacent to the indole. 3. 14C-TR-2, added to the perfusate of isolated rat liver, was excreted unchanged in the bile, implying no significant loss of any biliary TR-2 subject to enterohepatic recycling in vivo. 4. 14C-TR-2 incubated anaerobically in sheep ileum contents was 95% transformed into more polar metabolites, the majority of the radiolabelled metabolites isolated being water soluble. 5. The principal fate of biliary TR-2 is as a metabolic substrate for the intestinal microflora.     

Isolation from the serum of cancer patients and molecular structure determination of a ketone derivative of D3 vitamin

In a previous article we have reported our finding of an unknown vitamin derivative in the serum of cancer patients and in rats transplanted by a malignant tumor. Analysis of this compound extracted from serum of cancer patients, was carried out by I.R., U.V., mass spectrography and nuclear magnetic resonance (N.M.R.) determination. This analysis led us to the conclusion that the compound was a ketone derivative of D3 vitamin: 1-ceto-24-methyl-25-hydroxycholecalciferol, provisionally designated D3C. Enzymatic pathways involved in the biosynthesis of this substance and its possible role in normal and pathological cell division are discussed.     

Young adult chronic patients: visibility and style of interaction in treatment

To explore the concept of the young adult chronic patient as a distinct clinical entity, the author analyzed a sample of 134 chronic patients on six variables relating to style of interaction with service providers and on diagnostic and demographic variables. The results showed that the 105 younger chronic patients in the sample were more likely than the older patients to be male, to be referred to treatment for suicidal and homicidal gestures and ideation, to have a diagnosis of personality disorder, and to be overrepresented in the treatment population. The author believes the combination of these factors helps create disproportionately high visibility for young adult chronic patients and requires special provisions for their engagement in treatment.