Energy metabolism of rabbit retina as related to function: high cost of Na+ transport

Experiments designed to examine the energy requirements of neurophysiological function were performed on isolated rabbit retina. Function was altered by photic stimulation or by function-specific drugs, and the response of energy metabolism was assessed by simultaneous measurements of O2 consumption and lactate production. In other experiments, the supply of O2 or glucose was reduced and the effect on energy metabolism and electrophysiological function was observed. Energy requirements under control conditions in darkness were high, with O2 consumption (per gm dry wt) at 11.3 mumol min-1, with lactate production at 14.8 mumol min-1, and with the derived value for glucose consumption at 9.3 mumol min-1 and for high-energy phosphate (approximately P) generation at 82.6 mumol min-1. Energy reserves were small. Removing glucose abolished the b-wave of the electroretinogram (ERG) with a t1/2 of 1 min, but did not immediately affect O2 consumption or the PIII of the ERG. Removing O2 caused increases of up to 2.7-fold in glycolysis (Pasteur effect) and caused both PIII and b-wave to fail, with a t1/2 of about 5 min. Neurotransmission through the inner retina was supported almost entirely by glycolysis, as evidenced by large increases in lactate production in response to flashing light and decreases in response to transmitter blockers (2.3-fold overall change), with no change in O2 consumption. Phototransduction, on the other hand, was normally supported by oxidative metabolism. The dark current accounted for 41% of the retina's O2 consumption. With O2 reduced, the dark current was partially supported by glycolysis, which accounts (at least in part) for the large Pasteur effect. Na+ transport by NaK ATPase accounted for about half of all energy used, as evidenced by the response to strophanthidin, that is, for 49% of the oxidative energy and 58% of the glycolytic energy. The t1/2 for the turnover of intracellular Na+ was calculated from these data to be less than 1 min. Changes in temperature caused changes in the amplitude of light-evoked electrical responses of 6.5% per degree and caused changes in both O2 consumption and glycolysis of 6.8% per degree (Q10 = 1.9). A surprisingly large fraction of oxidative energy, corresponding to about 40% of the total energy generated, could not be assigned to phototransduction, to neurotransmission, to Na+ transport for other purposes, or to vegetative metabolism. We cannot account for its usage, but it may be related to the (previously reported) rapid turnover of the gamma-phosphate of retinal GTP, the function of which also remains unknown.(ABSTRACT TRUNCATED AT 400 WORDS)

Differential inhibition of human basal keratinocyte growth to silver sulfadiazine and mafenide acetate

The impact of topical antimicrobial agents on improving the survival of patients with major thermal injuries is significant. However, the effects of these agents on cells responsible for wound healing has only recently received attention. Fresh human basal keratinocytes were grown in serum-free modified MCDB 153 medium under standard tissue culture conditions. Cells were subsequently exposed to concentrations of silver sulfadiazine and mafenide acetate as low as 1/100 of that used clinically over a period of 5-7 days. Cellular responses documented with hemocytometer cells counts, cellular protein assays, phase-contrast microscopy, and transmission electron microscopy show only severe toxicity to mafenide acetate. Such data imply that inhibition of wound epithelialization is greater with the use of mafenide acetate than with the use of silver sulfadiazine.

Characterization of a circular plasmid from the yeast Kluyveromyces waltii

A new plasmid was found in the yeast Kluyveromyces waltii. This high-copy-number plasmid, named pKW1, is a double-stranded circular DNA plasmid of 5619 bp. It has several features characteristic of the 2 mu-type plasmids: presence of two inverted repeats and four open reading frames, as well as the interconversion of two isomeric forms. However, the nucleotide sequence shows little homology with known yeast plasmids. An ARS function was localized within a segment of 545 bp near one of the inverted repeats. Chimeric plasmids carrying this segment efficiently transformed K. waltii. A strain of K. waltii cured of the plasmid (cir degree) was also obtained. In the pKW1 sequence, a functionally neutral region was found at which foreign DNA can be inserted with little effect on plasmid stability. Such constructions carrying the full sequence of pKW1 replicated autonomously in a cir degree host and were particularly stable. pKW1-derived full-sequence plasmids also transformed K. thermotolerans, but not K. lactis.

Changes in serum osmolality and osmolar discrepancy in burned patients

Forty-three patients with burns of various depth and burn surface area were studied to determine the relationship between burn severity and changes of serum osmolality. The results showed that the osmolality in four patients who died were significantly higher than the osmolalities of survivors with very serious burns, whose osmolalities decreased gradually to normal level. Hyperosmolality and obvious osmolar discrepancy often co-exist. It is suggested that the changes of osmolality and osmolar discrepancy can reflect the burn severity and prognosis of the patients.

[Experimental research on the effective mechanism of jianweiling]

The purpose of this study is to find out the effective mechanism of Jianweiling (JWL) in treating some gastrointestinal (GI) diseases. The functions of GI movement, bile and pancreatic secretion and intestinal absorption were measured after giving JWL to the experimental rats. The results showed that JWL could adjust GI movement once it was in abnormal conditions. When the gastrointestine was in paralysis under the influence of abdominal operation, JWL could make GI myoelectric activity return to normal; and JWL could relax it when the gastrointestine was in a cramp state resulted from Neostigmini Methylsulfurici injection. In addition, the pancreatic secretion, the amylase activity in pancreatic juice and the intestinal absorption for D-xylose in JWL group were obviously better than those of the control groups. These results suggested that the effective mechanism of JWL on some GI diseases can be realized by adjusting and promoting GI functions in various ways.

A new human interferon-gamma mutant harboring EGF receptor-interfering sequence possesses high antiproliferative activity

An interferon gamma (IFN-gamma) mutant gene harboring an additional epidermal growth factor (EGF) sequence at its 3' terminal was constructed and highly expressed in E. coli by using pBV220 as a vector. The new fusion protein-IFN-gamma-EGF possesses not only high antiviral activity, but also high antiproliferative effect as demonstrated by 3H-TdR incorporation method using CN II cells which are rich in EGF receptors.

Synthesis and secretion of human atrial natriuretic peptide in Saccharomyces cerevisiae

A chemically synthesized alpha-hANP gene was inserted into plasmid YFD18, which was an expression-secretion vector of yeast. The recombinant then transformed in the yeast Y33. The expression level of yeast transformants was about 700 micrograms ANP/L detected by RIA. More than 99% of expression products were secreted in the culture medium. N-terminal analysis of purified product showed that the first 4 amino acid residues of alpha-hANP were deleted.

Dimensions of face in Asia in the perspective of geography and prehistory

Data from 24 craniofacial dimensions were compiled for samples representing all the human populations of the world. These were converted into C scores and used to construct Euclidean Distance dendrograms. The populations of the world are best depicted as 8 major regional clusters representing: Africa, Amerind, Asia-Mainland, Australo-Melanesia, Eskimo-Siberia, Europe, India, and Jomon-Pacific. The mainland Asian cluster divided into northern and southern components. The Neolithic in both areas is less clearly associated with the northern or southern components and may represent the form of their undifferentiated precursors. This needs to be tested by the addition of further specimens and an adequate sample from South China. Mongols are peripheral members of the Asia-Mainland cluster and should not be thought of as typifying the region as a whole. The use of the term "Mongoloid" is inappropriate in both theory and practice.

Evaluation of HemoQuant test and enteroclysis in estimating the sites of obscure gastrointestinal bleeding

The HemoQuant test includes the measurement of total fecal hemoglobin (Hb) or porphyrin derived from heme, and of intestinal converted fraction (ICF) which is the performed porphyrin probably by bacteria during enterocolic transit. The mean +/- SD of HemoQuant in 31 healthy subjects was 0.57 +/- 0.49 mg Hb/g stool, values above 2 mg Hb/g stool are considered to be positive. In patients with upper GI bleeding (n = 44), small bowel bleeding (n = 11) and large bowel bleeding (n = 16), the ICF ranged 0.03-23%, 0.09-20.20% and 0.35-11.0%, respectively. There was major overlap in individual ICF due to some influencing factors such as the quantity of fecal blood and the enterocolic transit. We conclude that HemoQuant is a sensitive assay for detection of fecal occult blood, but ICF is not helpful in estimating the anatomic site of bleeding. Seventy-one patients with GI bleeding of obscure origin underwent enteroclysis. The results showed 77.5% had definite lesions in the small bowel, but 22.5% still were undefined. It is suggested that enteroclysis should be performed without delay if upper and lower GI endoscopic studies are negative.

The prevalence of Helicobacter pylori infection in the Peoples Republic of China

Meta-analysis on data from 16 (two volunteer and 14 endoscopic) studies ahs been performed to investigate the prevalence of Helicobacter pylori infection in the stomachs of individuals within the Peoples Republic of China. In this survey covering 2216 cases (89 volunteers and 2127 endoscopy patients), the incidence of H. pylori infection in 15- to 22-yr-old healthy volunteers, and in 13- to 88-yr-old symptomatic patients undergoing gastroscopy was 49.4% and 64.5%, respectively. The frequency of H. pylori infection in chronic gastritis (63.6%), gastric ulcer (71.9%), and duodenal ulcer disease (73.1%) differed significantly from that in histologically normal individuals (8.2%), confirming the relationship of H. pylori infection with those disease states. We found no significant association between H. pylori infection and symptoms.

Viral etiology of chronic cervicitis and its therapeutic response to a recombinant interferon

Chronic cervicitis was shown to be related to papillomavirus type 16(HPV-16), herpes simplex virus type 2 and cytomegalovirus (CMV) infections as demonstrated by DNA hybridization technique and virus isolation method from samples taken from erosive and normal cervices. After one course of treatment with recombinant interferon alpha 1 (rIFN-alpha 1), 93.8% of cases showed clinical improvement and 60% marked improvement. The HPV-16 and HSV detection rates dropped down significantly after rIFN-alpha 1 treatment as compared with those before treatment. Astragalus membranaceus, a Chinese herbal drug, was shown to be synergic to interferon therapy.

Seroepidemiology of herpes simplex virus type 1 in Yanji, Jilin, China

Sera from 158 individuals in Yanji, Jilin, China, were tested for antibodies to herpes simplex virus type 1 (HSV-1) by the passive hemagglutination method. Age-specific incidence rates for antibodies to HSV-1 were calculated. For sera from persons in the age group 10 years or less, the positive rate was 54% but in the age group higher than 10 years, it was more than 91% (P less than 0.01). In the part of China surveyed, primary HSV-1 infection occurred in early generation before about age 10. In children, the positive rate in the Han race was significantly higher than that in the Korean race (P less than 0.05).

[Adult diarrhea rotavirus in Jilin, China]

In May 1986, an outbreak of epidemic acute diarrhea occurred in one city and three counties in Yanbian area. The diarrheal cases were seen in all age groups, the majority of the cases were seen in adult age group. No bacterial pathogens were isolated in 22 fecal samples examined, however rotavirus like particles of 52-68 nm in diameter were found in 50% (11/22) of fecal samples by the immunoelectron microscopy using convalescent sera. Examination by the adult diarrhea rotavirus (ADRV) ELISA kit showed positive reaction in 86% (6/7) of fecal extracts, however in all 22 fecal extracts examination using ELISA kit for detection of group A rotavirus showed negative reaction. The PAGE patterns of viral RNAs similar to those of ADRV were seen in 13 out of 22 fecal extracts. The detection rate by PAGE analysis was 59%. Based on the above data, the etiological agent of the epidemic acute diarrhea, which occurred in Yanbian area, was identified to be ADRV.

[Clinical classification of altitude sickness: analysis of 13,403 cases]

The clinical classification and characteristics of various types of plateau sickness were reported after analysing 13,403 such cases in Tibet region. The conception of plateau sickness and the opinion of its classification in China and abroad were discussed and the names suggested for various types of the disease were also given. However, the rationality of different classifications of the sickness was questioned according to the present understanding of its pathology and clinical manifestations. It is the opinion of the authors to divide this sickness, first of all, into two categories of acute and chronic and then to subdivide each of them into several types according to clinical symptoms and the pathological changes of principally encroached organs. The acute category was subdivided into 4 types as follows: 1. high altitude acute response (HAAR); 2. high altitude pulmonary edema (HAPE); 3. high altitude cerebral edema (HACE); 4. high altitude children cardiopathy (HACC). The chronic category was subdivided into 5 types as follows: 1. high altitude chronic response (HACR); 2. high altitude erythoblastosis (HAEb); 3. high altitude adult cardiopathy (HAAC); 4. high altitude hypertension (HAHyper); 5. high altitude hypotension (HAHypo). This classification is useful in clinical practice and research.

[Changes in serum osmolality and osmolar discrepancy in burn patients]

43 patients with burns of various degree and TBSA were investigated to study the relationship between burn severity and changes of serum osmolality. The results showed that the osmolality in 4 dead patients was significantly higher than the osmolality of the survivors with very serious burns, whose osmolality decreased gradually to normal. Hyperosmolality and obvious osmolar discrepancy often exist simultaneously. It is suggested that the changes of osmolality and osmolar discrepancy can reflect the burn severity and the prognosis of the patients.

Exocrine pancreatic function tests

Despite the development in the last two decades of new imaging techniques for the detection of pancreatic disease, discrepancies between functional and morphological findings can be remarkable. Pancreatic function tests may aid in the detection of disease at an earlier stage in some patients and can assess the degree of functional damage which is helpful in assessing patients for supplemental therapy. While direct intubation methods are invasive and time consuming, they remain the gold standard against which the other investigations have to be assessed. An indirect test, such as the pancreolaural test, has been shown to be a useful addition to ultrasound for the screening of pancreatic disease. Pancreatic markers and radioisotope methods have failed to live up to early promise, but fecal tests can be used effectively to monitor enzyme replacement. A judicious combination of pancreatic function tests and imaging techniques may be able to rationalize investigation and treatment of pancreatic disease.

[A study on the triglyceride clearance in the perioperative period]

Native Chinese have been used to low fat diet for long history. To evaluate the tolerance of 50% fat caloric source in Chinese patients will be valuable in medical science and clinical practice. Triglyceride (TRG) clearance was studied in research ward in the period of 1986-1987. The results showed that POD + 7 TRG clearance was better than AOD-3. No functional disorders of the liver, heart, and kidney were found after 11 days of total parenteral nutrition support with mixed energy.

[Clinical and experimental studies on the effect of xue mai tong on coronary heart disease]

This article deals with the treatment of hypercoagulability with CHD by the mechanism of resolving phlegm and alleviating stagnation on the basis of the viewpoints that "body fluid and blood are derived from the same source" and that "Phlegm and blood are of the same stasis". The study on 74 patients who received Xue Mai Tong and 31 controls who were treated by promoting blood circulation to remove stasis showed an overall effective rate of 85.13% (63 cases) and a evident effective rate of 59.46% (44 cases) for angina pectoris in the treatment group. The efficacy of the treatment group with Xue Mai Tong was proved to be better than that of the controls (P less than 0.05). Animal experiments demonstrated that Xue Mai Tong improved microcirculation perfusion as compared with the controls (P less than 0.05) as evaluated by the length and wet weight of the thrombus.

The expression of HBsAg gene in yeast under GAL-10 promoter control

The surface antigen gene of HBV (adr subtype) is inserted into the YEP 1 which is replicated and selected in E. coli and baker yeast Saccharomyces cerevisiae. The HBsAg gene can be expressed in yeast under GAL-10 promoter control. The protein synthesized in yeast is assembled into particles that have the same size and shape as particles isolated from plasma. One microgram surface antigen can be yielded in 100 ml culture.