Kidney function in stainless steel welders

Summary Seventeen male manual metal-arc stainless steel welders (mean exposure time 20 years) had far higher levels of chromium in urine than individually matched controls (medians 23 vs 1.5 mol/mol creatinine;10.5 vs 0.7 g/g creatinine). However, there were no signs of kidney damage in tests of function of tubuli (-hexosaminidase, lysozyme, and ₂-microglobuline) or glomeruli (albumine clearance).     

Human myeloma light chains with increased molecular weight: high frequency among lambda chains

The discovery of a human myeloma protein comprising a kappa L-chain with an increased mol. wt of 30,000) (Bouvet et. al., 1980) prompted investigations on the incidence of such heavier L-chains among other human myeloma proteins. In 105 samples examined, 34 were found to have L-chains heavier than normal (23,000-24,000), ranging from 25,000 up to 31,000, and five of lighter mol. wt (21,000-22,000). These mol. wt abnormalities were detected by electrophoresis in sodium dodecyl sulfate 10% polyacrylamide gels (SDS-PAGE) after reduction with 2-mercaptoethanol. The mol. wt of three of the heavier kappa or lambda chains was also estimated by filtration through a Sephadex G100 column and by sedimentation equilibrium. All three methods indicated a mol. wt increase of about 15-25% as compared with the usual mol. wt. The distribution of the high mol. wt chains among all L-chains examined was found to be 11 out of 62 kappa chains (17.7%) and 23 out of 43 lambda chains (53%) (P less than 0.001). A preferential association of such L-chains with H-chains producing multiple bands in SDS-PAGE (P less than 0.01) and an association between multiple L-chain and multiple H-chain band (P less than 0.05) were also observed. In contrast, no abnormal L-chain was found in immunoglobulins from normal subjects. Spontaneous degradation of the normal H-chains sometimes yielded fragments of 30,000 mol. wt. These fragments were easily distinguishable from abnormal L-chains. The nature of extra mol. wt in heavy L-chains was investigated for the presence of carbohydrate moiety. Four large and three normal size L-chains were examined for amino-sugar and sialic acid content. A small amount (one residue per molecule) of amino-sugar was detected only in two normal and two heavy L-chains, whereas sialic acid was only found in the heaviest (27,000-30,000) L-chains (Lh) and in small percentage (one or two residues per molecule). Total sugar estimation in one Lh chain indicated a proportion not exceeding three or four residues per L-chain (mol. wt 1,000) and this is insufficient to explain the 15-25% (3,600-6,000) mol. wt increase. It is therefore possible that, at least in some heavy myeloma L-chains, an additional peptide is expressed. Whatever the nature of the increase it would be of interest to elucidate whether this is a marker of malignant process or of an intermediate step of normal Ig synthesis.     

Does the washout phenomenon of Tc-99m HM-PAO correlate to the “Filling-in” phenomenon of I-123 IMP with brain SPECT?

Summary Using SPECT, the time course of brain uptake was compared between N-isopropyl-p-[I-123]-iodoamphetamine (I-123 IMP) and Tc-99m d,l hexamethyl-propyleneamine oxime (Tc-99m HM-PAO). Of 14 patients with cerebrovascular disease showing areas of the filling-in phenomenon (i.e. delayed uptake) with I-123 IMP brain SPECT, 7 exhibited persistent defects with Tc-99m HM-PAO (Group I), and 7 showed early washout after the initial uptake (Group II). The filling-in of I-123 IMP did not always correlate to the washout region of Tc-99m HM-PAO. The temporal changes were also confirmed by semiquantitative analysis. While the filling-in of I-123 IMP was affected by many factors, the washout of Tc-99m HM-PAO was attributed to significant reduction of Tc-99m HM-PAO in the plasma. Delayed imaging of the brain with Tc-99m HM-PAO using SPECT may give a more accurate estimate of regional cerebral blood flow in cerebrovascular disease, because it should be lees effected by cerebral blood volume.     

Detection of traumatic myocardial injury by means of simultaneous T1-201/Tc-99m pyrophosphate tomography--report of three cases

Trauma to the chest can result in cardiac damage, which maybe missed by clinical examination because of associated injuries.Routinely performed non-invasive tests may also be non-diagnostic.Tc-99m pyrophos-phate (PPi) tomography, in this study combinedwith T1-201, is a promising addition to non-invasive evaluation.In three patients with cardiac injury, this technique successfullydetected and localized myocardial necrosis.     

Einflu\ eines Β1-Rezeptorenblockers auf die Plasmaspiegel des atrialen natriuretischen Peptids bei Patienten mit essentieller Hypertonie unter Ergometerbelastung

Summary In order to investigate the behaviour of atrial natriuretic peptide (ANP) in untreated mild to moderate essential hypertension and the influence of blood pressure normalisation by a ₁-receptor blocker a study was conducted in groups of normotensive and hypertensive middle aged subjects. 10 normal subjects and 10 patients with essential hypertension (WHO I–II) without any medication and on betaxolol monotherapy were studied at rest and during graded exercise. In addition the response of ANP, cyclic guanosine monophosphate (cGMP) and the renin-aldosterone-system was investigated.Normal subjects and hypertensive patients did not differ in ANP levels at rest and also responded with a comparable exercise dependent increase at all workload levels. A steady decrease of ANP was noticed during the recovery period in both groups. After-blocker treatment in the hypertensive patients ANP concentrations significantly rose, both at rest and more pronounced during exercise. cGMP reacted in a similar way but showed a more inert response. A counter-regulatory behaviour between ANP and PRA or aldosterone, as seen under volume shifts, could not be detected. These findings demonstrate that plasma ANP is not altered in untreated essential hypertension. Increased ANP levels in ₁-blocker treatment may contribute to its blood lowering effect.

---

Abkürzungsverzeichnis ANP atriales natriuretisches Peptid - ALD Aldosteron - C_In Inulin Clearance - cGMP zyklisches Guanosinmonophosphat - irANP immunoreaktives atriales natriuretisches Peptid - PAH Paraaminohippursäure - PRA Plasma-Renin-Aktivität - RAA-System Renin-Angiotensin-Aldosteron-System - RBF renaler Blutflu - RIA Radioimmunoassay - RVR renaler Gefä\widerstand     

Oral senile amyloidosis in senescence accelerated mouse (SAM)

Oral senile amyloidosis in senescence accelerated mouse (SAM) was examined for two SAM sublines (P/2/Iw and R/1/Iw) and for various ages by light microscopy, immunohistochemistry, and electron microscopy. The amyloid deposition, identified by green birefrigence following Congo red stain, was observed only in P/2/Iw. In P/2/Iw, no amyloid deposition was found at age 6 months; however, frequency and extent of such deposits increased with advancing age. Distribution of amyloid deposition was as follows: along papillary layers of mucous epithelium in the tongue, the gingiva, the palate, and the buccal mucosa; foci in connective tissues; along vessels, muscles, and minor salivary glands. Immunohistochemically, the amyloid deposition was positive with anti-ASSAM serum being raised against a unique amyloid protein ASSAM which probably induced "senile systemic amyloidosis". P/2/Iw is useful as an animal model of oral senile amyloidosis.     

Immunocytochemical distribution of S-100 protein in patients with Down's syndrome

Summary The immunohistochemical distribution of S-100 protein in patients with Down's syndrome was investigated as part of a study aimed at ascertaining a possible involvement in the syndrome (trisomy 21) of this protein, which has recently been shown to be coded in chromosome 21. No appreciable differences in the cell distribution of the antigen could be observed between patients with Down's syndrome and normal subjects. The possibility of an overexpression or abnormal expression of the molecule as a consequence of chromosome 21 triplication, not detectable by immunocytochemical methods alone, remains to be investigated.Supported in part by grants from Consiglio Nazionale delle Ricerche and Ministero della Pubblica Istruzione to F. M. and L. L.     

Prejunctional inhibition of sympathetically evoked pupillary dilation in cats by activation of histamine H3 receptors

Summary Frequency-dependent pupillary dilations were evoked by electrical stimulation of the pre- or post-ganglionic cervical sympathetic nerve (sympatho-excitation) or the hypothalamus (parasympatho-inhibition) in sympathectomized anesthetized cats. Systemic administration of the selective histamine H₃ receptor agonist (R)--methylhistamine (RMeHA) produced a dose-dependent depression of mydriasis due to direct neural sympathetic activation but had no effect on responses elicited by parasympathetic withdrawal. The histamine H₂ receptor agonist, dimaprit, was inactive. RMeHA was much more effective in depressing sympathetic responses obtained at lower frequencies when compared to higher frequencies of stimulation.Responses evoked both pre- and postganglionically were inhibited by RMeHA. This peripheral sympathoinhibitory action of RMeHA was antagonized by the histamine H₃ receptor blocker thioperamide but not by intravenous pretreatment with the histamine H₁ receptor antagonist chlorpheniramine. Histamine H₂ receptor blockers cimetidine and ranitidine were also without effect. RMeHA did not depress pupillary responses elicited by i.v. (-)-adrenaline.The results demonstrate that histamine H₃ receptors modulate sympathetic activation of the iris at a site proximal to the iris dilator muscle. The predominant mechanism of action appears to the prejunctional inhibition of noradrenaline release from postganglionic sympathetic nerve endings. However, a concomitant ganglionic inhibitory action cannot be excluded. Correspondence to M. C. Koss at the above address     

Intrathecal IgM response in disseminated cerebrospinal metastasis from malignant melanoma

Summary Neurological complications are a major cause of morbidity and mortality in patients with disseminated malignant melanoma. We have studied and correlated clinical and cerebrospinal fluid (CSF) findings in 20 patients with central nervous system metastases from malignant melanoma including 8 patients with metastatic meningeal melanomatosis (MMM) and 12 patients with solid cerebral metastases (SCM). The putative CSF tumor markers, fibronectin and ₂-microglobulin, were elevated significantly in MMM but not in SCM patients. A prominent increase in the IgM index, which reflects intrathecal B-cell stimulation, and a rise of IgG index, interleukin-6, and tumor necrosis factor- in MMM patients provide preliminary evidence for a local intrathecal immune response triggered by melanoma cell invasion of the subarachnoid space.     

Hydrolysis of Carbonates,Thiocarbonates, Carbamates,and Carboxylic Esters of α-Naphthol, β-Naphthol,and p-Nitrophenol by Human,Rat, and Mouse Liver Carboxylesterases

Thirty carbonates, thiocarbonates, carbamates, and carboxylic esters of -naphthol, -naphthol, and p-nitrophenol were synthesized and tested as substrates for liver carboxylesterases from the crude microsomal fractions of human and mouse, and purified isozymes, hydrolases A and B, from rat liver microsomes. The carbonates, thiocarbonates, and carboxylic esters of -naphthol were cleaved more rapidly than the corresponding -naphthol isomers by the mammalian liver esterases. -Naphthyl esters of acetic, propionic, and butyric acids were among the best substrates tested for these enzymes. The majority of the substrates was consistently hydrolyzed at higher rates by hydrolase B compared with hydrolase A, although the Michaelis–Menten constant (K _m) values of selected substrates differed widely with these two isozymes. Malathion was a 15-fold better substrate for hydrolase B than for hydrolase A. Compared with the corresponding carboxylates, the carbonate moiety of - and -naphthol and p-nitrophenol lowered the specific activities of the enzymes by about fivefold but improved stability under basic conditions. The optimum pH of mouse liver esterase with the acetate, methylcarbonate, and ethylthiocarbonate of -naphthol was between pH 7.0 and pH 7.6. Human and mouse liver microsomal esterase activities were about five orders of magnitude lower than the esterase activities of purified rat liver hydrolase B. A relationship between the catalytic activity of the enzymes and the lipophilicity of the naphthyl substrates indicated that (i) in the - and -naphthyl carbonate series, an inverse relationship between enzyme activity and lipophilicity of the substrates was observed, whereas (ii) in the -naphthyl carboxylate series, an increase in enzyme activity with increasing lipophilicity of the substrates up to a log P value of about 4.0 was observed, after which the enzyme activity decreased.