ONYCHOMYCOSIS OF THE FEET—Treatment with Griseofulvin

Griseofulvin, a new orally administered antifungal antibiotic which has proved to be effective for the treatment of a wide variety of superficial fungus infections of man, was used in the treatment of 51 patients with infections of the toenails due to T. rubrum. Thirty-four of the patients were treated with griseofulvin alone and seven were treated with griseofulvin combined with surgical avulsion of all involved toenails. The remaining ten had bilateral infections, and avulsion was done on one foot but not the other before griseofulvin therapy was begun.Of 34 patients who were treated with griseofulvin alone, few had complete cure even after prolonged treatment. Some nails showed improvement for a time, then no further gain; some showed no improvement; some showed resistant wedges of infection which penetrated proximally toward the posterior nail fold.In the instances of surgical avulsion, clinically normal nails regrew during griseofulvin therapy. This simple procedure, with thorough removal of all underlying keratinous debris, apparently did away with foci of possible reinfection.The results of the study indicated that surgical avulsion of the toenails in combination with griseofulvin therapy is an effective and practical method of treating onychomycosis of the toenails due to T. rubrum.     

RADIATION THERAPY OF RINGWORM OF THE SCALP

A recent epidemic of tinea capitis in children has revived a considerable interest in the methods of treatment of this disease.The most efficacious form of therapy for M. audouini infections is roentgen epilation.The various methods of x-ray treatment are briefly presented and compared. A modification of the four-point technique is shown to offer a simple yet safe method of curing ringworm of the scalp. Results with this method compare favorably with the best of those reported by the use of other methods.Cure was effected by this method in all of a group of 125 cases.     

VIRULENCE OF MIXED-CLONE AND SINGLE-CLONE INFECTIONS OF THE RODENT MALARIA PLASMODIUM CHABAUDI

Most evolutionary models treat virulence as an unavoidable consequence of microparasite replication and have predicted that in mixed-genotype infections, natural selection should favor higher levels of virulence than is optimal in genetically uniform infections. Increased virulence may evolve as a genetically fixed strategy, appropriate for the frequency of mixed infections in the population, or may occur as a conditional response to mixed infection, that is, a facultative strategy. Here we test whether facultative alterations in replication rates in the presence of competing genotypes occur and generate greater virulence. An important alternative, not currently incorporated in models of the evolution of virulence, is that host responses mounted against genetically diverse parasites may be more costly or less effective than those against genetically uniform parasites. If so, mixed clone infections will be more virulent for a given parasite replication rate. Two groups of mice were infected with one of two clones of Plasmodium chabaudi parasites, and three groups of mice were infected with 1:9, 5:5, or 9:1 mixtures of the same two clones. Virulence was assessed by monitoring mouse body weight and red blood cell density. Transmission stage densities were significantly higher in mixed- than in single-clone infections. Within treatment groups, transmission stage production increased with the virulence of the infection, a phenotypic correlation consistent with the genetic correlation assumed by much of the theoretical work on the evolution of virulence. Consistent with theoretical predictions of facultative alterations in virulence, we found that mice infected with both parasite clones lost more weight and had on average lower blood counts than those infected with single-clone infections. However, there was no consistent evidence of the mechanism invoked by evolutionary models that predict this effect. Replication rates and parasite densities were not always higher in ???mixed-clone infections, and for a given replication rate or parasite density, mixed-clone infections were still more virulent. Instead, prolonged anemia and increased transmission may have occured because genetically diverse infections are less rapidly cleared by hosts. Differences in maximum weight loss occured even when there were comparable parasite densities in mixed- and single-clone infections. We suggest that mounting an immune response against more that one parasite genotype is more costly for hosts, which therefore suffer higher virulence.     

THE TREATMENT OF URINARY TRACT CALCULI

From review of recent information relative to calculus formation in the kidney, the conclusion reached that we do not yet understand, despite much effort, the basic physicochemical mechanisms involved. Since this is so, it has seemed best to the author for the present to rely, in treating patients with renal stones, on simple therapeutic concepts, which, if carefully and conscientiously applied, produce good results. The concepts are the elimination of known causes such as parathyroid adenomas and obstructive lesions, elimination or at least treatment of infections, diminution of urinary components which form the basis of calculi by limiting the oral intake or absorption from the gastrointestinal tract and maintenance of a dilute urine of desired pH.A plan for preoperative study is suggested to allow planned therapy. Indications for operative removal of calculi as well as some points of technique are discussed. It is emphasized that surgical removal of a calculus is but an incident in the care of patients with calculi and that treatment during the postoperative period and followup therapy is most important if success is to be achieved. Reports of cases to illustrate the application of these concepts are presented.     

THE EXPERIMENTAL AND CLINICAL USE OF POLYMYXIN,CHLOROMYCETIN, AND AUREOMYCIN

Polymyxin is an effective antibiotic for the treatment of severe infections produced by Ps. aeruginosa, H. pertussis, H. influenzae, E. coli, and A. aerogenes. Its toxicity to date precludes its general use in infections susceptible to its therapeutic effects.Chloromycetin has been demonstrated to be an effective antibiotic agent for the treatment of rickettsial diseases and typhoid fever. It will undoubtedly prove effective in the treatment of other infections produced by certain Gram-negative micro-organisms and viral agents.Aureomycin has been shown to be an active antibiotic agent against rickettsial diseases, primary atypical pneumonia, acute brucellosis, pneumococcal, streptococcal, and staphylococcal infections, urinary tract infections produced by E. coli, A. aerogenes and Strept. fecalis, certain types of infections of the eye, and in subacute bacterial endocarditis when the infecting agent is Strept. fecalis. Its clinical use in forms of extrapulmonary tuberculosis is in a completely experimental stage. It is not recommended in typhoid fever or in infections due to Ps. aeruginosa or P. vulgaris, and it seems to be ineffective in whooping cough.To date, neither chloromycetin nor aureomycin has shown significant signs of systemic toxicity.     

Management of hand and upper-extremity infections in heart transplant recipients

Hand and upper-extremity infections are routinely managed by antibiotics, immobilization, and limited incision and drainage. However, in immunocompromised patients, these infections may be more aggressive and they may require more emergent treatment. The authors performed a retrospective review of the Stanford University Medical Center experience with hand and upper-extremity infections in 911 cardiac transplant recipients over the past 30 years. Thirteen heart transplant recipients were treated for infections of the hand and upper extremity on an inpatient basis. Ten patients (77 percent) required operative debridement, and three (23 percent) required more than one operative procedure. Nine patients (69 percent) had bacterial infections, six (46 percent) had fungal infections [four of these patients (31 percent) had both bacterial and fungal infections], one (7.7 percent) had a mycobacterial infection, and one (7.7 percent) was not cultured. Hand and upper-extremity infections in transplant recipients frequently resulted in deep-space infections, tenosynovitis, and osteomyelitis. The authors believe such infections represent a surgical emergency, requiring immediate evaluation by hand surgeons and early, aggressive treatment.     

新疆维吾尔族手掌侧投影面积测定

应用WT-2型数字图像处理仪测定了123名维吾尔族青年手的掌侧投影面积。各指掌侧投影面积的平均值,以中指最大(15.32平方厘米),食指(13.72平方厘米)及环指(13.16平方厘米)次之,拇指再次(12.11平方厘米),小指最小(9.36平方厘米)。全手掌侧投影总面积平均156.97平方厘米。指掌侧投影总面积平均63.67平方厘米,占全手掌侧投影总面积的40.67％。手掌投影面积平均93.30平方厘米,占全手掌侧投影总面积的59.33％。按照Stevenson(1937)公式,根据身高和体重,计算出体表面积的估计值,进而求得全手掌侧投影面积占身体表面积的1.008％。经计算机处理,求得手长、手宽、身高、体重与手面积的相关系数,并建立了由手长和手宽推算手掌侧投影面积的多元回归方程。     

CHEMOTHERAPY,WITHIN‐HOST ECOLOGY AND THE FITNESS OF DRUG‐RESISTANT MALARIA PARASITES

A major determinant of the rate at which drug‐resistant malaria parasites spread through a population is the ecology of resistant and sensitive parasites sharing the same host. Drug treatment can significantly alter this ecology by removing the drug‐sensitive parasites, leading to competitive release of resistant parasites. Here, we test the hypothesis that the spread of resistance can be slowed by reducing drug treatment and hence restricting competitive release. Using the rodent malaria model Plasmodium chabaudi, we found that low‐dose chemotherapy did reduce competitive release. A higher drug dose regimen exerted stronger positive selection on resistant parasites for no detectable clinical gain. We estimated instantaneous selection coefficients throughout the course of replicate infections to analyze the temporal pattern of the strength and direction of within‐host selection. The strength of selection on resistance varied through the course of infections, even in untreated infections, but increased immediately following drug treatment, particularly in the high‐dose groups. Resistance remained under positive selection for much longer than expected from the half life of the drug. Although there are many differences between mice and people, our data do raise the question whether the aggressive treatment regimens aimed at complete parasite clearance are the best resistance‐management strategies for humans.     

CONSEQUENCES OF THE WIDESPREAD USE OF ANTIBIOTICS

Great quantities of antibiotics are used each year. A direct result has been the appearance of large numbers of infections caused by organisms that are resistant to the action of one or more of these drugs. A new syndrome, that of superinfection by bacteria resistant to an antibiotic being administered, has become common. Its recognition is of great importance.The control of resistant infections requires the development of new antimicrobial agents and new knowledge about the use of older ones in combination.The medical profession must be circumspect in its use of these important drugs or the time may come when the control of many serious infections may become impossible.     

THE INFLUENCE OF HOST DEMOGRAPHY ON THE EVOLUTION OF VIRULENCE OF A MICROSPORIDIAN GUT PARASITE

It is predicted that host exploitation should evolve to maximize parasite fitness and that virulence (= parasite-induced host mortality) evolves along with the rate of host exploitation. If the life expectancy of a parasite is short, it is expected to evolve a higher rate of host exploitation and therefore higher virulence because the penalty to the parasite for killing the host is reduced. We tested this hypothesis by keeping for 14 months the horizontally transmitted microsporidian parasite Glugoides intestinalis in mono-clonal host cultures (Daphnia magna) under conditions of high and low host background mortality. High host mortality, and thus parasite mortality, was achieved by replacing weekly 70–80% of all hosts in a culture with uninfected hosts from stock cultures (Replacement lines). In the low-mortality treatment no replacement took place. Contrary to our expectation, parasites from the Replacement lines evolved a lower within-host growth rate and virulence than parasites from the Nonreplacement lines. Across lines we found a strong positive correlation between within-host growth rate and virulence. We did further experiments to answer the question why our data did not support the predictions. Sporophorous vesicles (SVs, spore clusters) were smaller in doubly infected than in singly infected host-gut cells, indicating that competition within cells bears costs for the parasite. Due to our experimental protocol, the average life span of infections had been much higher in the Nonreplacement lines. Since the number of parasites inside a host increases with the time since infection, long-lasting infections led to high frequencies of multiply infected host-gut cells. Therefore, we speculated that within-cell competition was more severe in the Nonreplacement lines and may have led to selection for accelerated within-host growth. SVs in the Nonreplacement lines were indeed significantly larger. Our results point out that single-factor explanations for the evolution of virulence can lead to wrong predictions and that multiple infections are an important factor in virulence evolution.     

SOME ASPECTS OF THE BIOLOGY OF THE MARINE LEECH HEMIBDELLA SOLEAE

The biology of the marine leech Hemibdella soleae was studied. It was found that multiple infections were common, the leeches being attached by the posterior sucker to spines on the ctenoid scales of the upper surface of the sole. It was observed that in aqqaria they change position every few days, tending to migrate antoriorly and this orientation may perhaps be directed by the arrangement of the scales.
Cocoons, which are not deposited at 8 C or below, are attached to the shell fragments with which the soles camouflage themselves and the young leeches hatch after about forty-one days at 17 C. Leeches reach maturity about twenty-three days after finding a host and are fully grown after a further fortnight.
British Hemibdella seem to be confuned to Soleu solea although several other hosts (All Soleidae) have been recorded for this leech in the Mediterranean.     

兽类在流行病学中的作用

在各种疾病中,有些是与人类和动物都有关系的,如鼠疫、布鲁氏菌病、马堡热、拉萨热等,称为人兽共患疾病(Anthropozoonoses)。这些疾病的病原体既能传染给人又能传染给动物,造成人或兽类的疾病流行。在医学上也叫动物性病。据Hubbert(1975)等的统计有162种;约占人类传染病的1/5左右(耿贯一,1980)动物性病,实质是自然界中一个生物学现象和生态学问题。是生物间在一定地理景观(Landscape)中通过“食物链”联系演化成相互依存、相互制约、相互适应,并借以维持其种系延续的生物群落(Biocenosis或Community)的关系(1964)     

CRUSHING INJURY OF THE HAND—Prevention of Ischemic Contracture

Crushing injury of the hand usually causes “explosive” damage. Subsequent swelling of the palmar structures further impairs venous outflow, and hemorrhage into structural spaces increases the pressure. The arterial system and the large dorsal veins, however, are seldom obstructed and provide adequate circulation unless hampered by improper bandaging. A bandage that compresses the dorsal veins causes back-pressure, which increases the swelling further and brings about ischemia. Swelling and pain cause the patient to restrict exercise of the injured hand, which permits contractures to develop.The author has averted this sequence in more than 100 cases by preserving integrity of veins during debridement, arresting hemorrhage, bandaging the hand with compression dressings in functional flexion, and reducing swelling with hyaluronidase. In these cases, on removal of bandages in 24 hours, swelling was reduced and continued to diminish. All patients exercised the hand at this time without discomfort and only a few required aspirin for pain.     

THE BREEDING SEASON OF BIRDS IN THE LOWLAND RAINFOREST AND IN THE MONTANE FOREST OF WEST CAMEROON

An analysis is made of over a thousand precise bird breeding records for a forest area in West Cameroon. In the lowland forest there is no universal breeding season although most families have a preferred nesting season. On the other hand. in the montane forest breeding is seasonal and takes place in the drier months. These conclusions are supported by field observations and by the examination of over 5000 birds for gonad state, plumage wear and moult.
The remarkable difference in seasonality between the lowland and montane avifaunas is discussed with reference to climate, particularly to the mist which envelops the montane forest in the rainy season.     

THE NEWER PENICILLINS

The newer penicillins give high promise of overcoming some of the few disadvantages of penicillin-G.They fall into three groups: The alpha-phenoxy-penicillins; the penicillinase resistant penicillins; and the penicillins with enhanced activity against gram-negative bacteria.The newer alpha-phenoxy-penicillins offer little over alpha-phenoxy methyl penicillin (penicillin-V). As the length of the side chain is increased, absorption and attainable serum concentration is also increased, but these are questionable benefits and probably not significant for therapeusis.The penicillinase-resistant penicillins have once more brought almost all severe staphylococcal infections within therapeutic range. One of them, methicillin, must be administered parenterally. It is the agent of choice for the treatment of severe, penicillin-G resistant staphylococcal infections, and this is its only clinical indication. Another, oxacillin, which may be administered orally, is partially resistant to gastric acid degradation, but must be given on an empty stomach. It is most useful as prolonged therapy following methicillin, in the treatment of mixed hemolytic streptococcal-penicillin-G resistant staphylococcal infections, and as primary therapy for moderately severe penicillin-G resistant staphylococcal infections.The third group is still mostly in the experimental stage, but some strains of Proteus, E. coli, Salmonella and Shigella are highly vulnerable to their action.Toxic and allergic reactions to the newer penicillins, and crossed allergic reactions with penicillin-G, present unsolved problems.     

褶纹冠蚌外套膜组织培养的分泌物的偏光显微镜观察

以淡水育珠贝中珍珠形成较快的褶纹冠蚌为材料,用相差显微镜观察组织培养的外套膜的分泌物的形成和变化,用偏光显微镜观察分泌物的双折射现象,并与活体外套膜的分泌物、贝壳的角质层、棱柱层、珍珠层的双折射现象进行比较。结果表明;离体培养的外套膜细胞不仅能产生活体细胞相同的分泌物,而且分泌物还能在培养过程中形成结晶,并逐渐生长。发现外套膜的不同部位分区培养所形成的分泌物的性状与结晶性质和活体有一致性,表明组织培养的外套膜小片具有贝体原来的组织结构、分化特征和分泌功能。     

论季雨林的水平地带性

季雨林是受制于湿度因子的经度地带性植被类型,它是随着湿度条件的下降由热带雨林向热带疏林过渡的居间类型,而不是受制于温度因子的纬度地带性植被类型,不是随着温度条件的下降由热带雨林向亚热带常绿阔叶林过渡的居间类型。我国南亚热带的榕树群系、黄桐群系,以及热带北缘的青皮群系均不应是季雨林,前二者是典型的南亚热带低地常绿阔叶林或南亚热带雨林,后者则是热带雨林的一分类群。     

MANAGEMENT OF RESECTABLE LESIONS OF THE SMALL BOWEL

During a 12-year period at the Los Angeles County General Hospital there were 364 cases of resection and anastomosis of the small intestine which were classified and studied. Particular attention was paid to the methods of anastomosis. There were more wound infections, fistulas and otherwise faulty anastomosis with the open than with the closed technique. In the presence of a peritoneal cavity not previously contaminated by bowel content, a closed anastomosis is better and safer than an open anastomosis.     

A STUDY OF THE STRUCTURE AND DISTRIBUTION OF THE NEXUS

Nexuses, that is, fusions of plasma membranes of adjacent cells, are described in mammalian smooth and cardiac muscle, median giant axon of earthworm, frog skin, and rat submandibular gland. In smooth muscle they usually occur where a process from one cell either meets a process of, or projects into a neighboring cell. On the other hand, in mammalian heart muscle and in earthworm giant axon the nexuses occur along the intercalated disc and intercellular segmental septa, respectively. Their occurrence between these excitable cells is correlated with propagation of action potentials by an electrical rather than chemical mechanism. Since the nexuses may offer pathways for electric current between cell interiors, it seems possible that they constitute a link in the structural basis for electrical transmission in these systems. In epithelia, nexuses usually appear as part of a terminal bar complex. This is true in the rat salivary gland studied here. In the epidermis of frog skin, nexuses are less numerous between the basilar columnar cells than between the subjacent squamous cells. The nexuses which occur in epithelia in frog skin and rat salivary gland are distributed as though to provide seals against electrochemical backleaks and sites of chemical exchange between cell interiors.     

INFLUENCE OF A SLIGHT MODIFICATION OF THE COLLODION MEMBRANE ON THE SIGN OF THE ELECTRIFICATION OF WATER

1. It is shown that collodion membranes which have received one treatment with a 1 per cent gelatin solution show for a long time (if not permanently) afterwards a different osmotic behavior from collodion membranes not treated with gelatin. This difference shows itself only towards solutions of those electrolytes which have a tendency to induce a negative electrification of the water particles diffusing through the membrane, namely solutions of acids, acid salts, and of salts with trivalent and tetravalent cations; while the osmotic behavior of the two types of membranes towards solutions of salts and alkalies, which induce a positive electrification of the water particles diffusing through the membrane, is the same. 2. When we separate solutions of salts with trivalent cation, e.g. LaCl₃ or AlCl₃, from pure water by a collodion membrane treated with gelatin, water diffuses rapidly into the solution; while no water diffuses into the solution when the collodion membrane has received no gelatin treatment. 3. When we separate solutions of acid from pure water by a membrane previously treated with gelatin, negative osmosis occurs; i.e., practically no water can diffuse into the solution, while the molecules of solution and some water diffuse out. When we separate solutions of acid from pure water by collodion membranes not treated with gelatin, positive osmosis will occur; i.e., water will diffuse rapidly into the solution and the more rapidly the higher the valency of the anion. 4. These differences occur only in that range of concentrations of electrolytes inside of which the forces determining the rate of diffusion of water through the membrane are predominantly electrical; i.e., in concentrations from 0 to about M/16. For higher concentrations of the same electrolytes, where the forces determining the rate of diffusion are molecular, the osmotic behavior of the two types of membranes is essentially the same. 5. The differences in the osmotic behavior of the two types of membranes are not due to differences in the permeability of the membranes for solutes since it is shown that acids diffuse with the same rate through both kinds of membranes. 6. It is shown that the differences in the osmotic behavior of the two types of collodion membranes towards solutions of acids and of salts with trivalent cation are due to the fact that in the presence of these electrolytes water diffuses in the form of negatively charged particles through the membranes previously treated with gelatin, and in the form of positively charged particles through collodion membranes not treated with gelatin. 7. A treatment of the collodion membranes with casein, egg albumin, blood albumin, or edestin affects the behavior of the membrane towards salts with trivalent or tetravalent cations and towards acids in the same way as does a treatment with gelatin; while a treatment of the membranes with peptone prepared from egg albumin, with alanine, or with starch has no such effect.