BRAFΔβ3-αC in-frame deletion mutants differ in their dimerization propensity, HSP90 dependence, and druggability

In-frame BRAF exon 12 deletions are increasingly identified in various tumor types. The resultant BRAFΔβ3-αC oncoproteins usually lack five amino acids in the β3-αC helix linker and sometimes contain de novo insertions. The dimerization status of BRAFΔβ3-αC oncoproteins, their precise pathomechanism, and their direct druggability by RAF inhibitors (RAFi) has been under debate. Here, we functionally characterize BRAFΔLNVTAP>F and two novel mutants, BRAFdelinsFS and BRAFΔLNVT>F, and compare them with other BRAFΔβ3-αC oncoproteins. We show that BRAFΔβ3-αC oncoproteins not only form stable homodimers and large multiprotein complexes but also require dimerization. Nevertheless, details matter as aromatic amino acids at the deletion junction of some BRAFΔβ3-αC oncoproteins, e.g., BRAFΔLNVTAP>F, increase their stability and dimerization propensity while conferring resistance to monomer-favoring RAFi such as dabrafenib or HSP 90/CDC37 inhibition. In contrast, dimer-favoring inhibitors such as naporafenib inhibit all BRAFΔβ3-αC mutants in cell lines and patient-derived organoids, suggesting that tumors driven by such oncoproteins are vulnerable to these compounds.

Mast cell deficiency prevents BCR::ABL1 induced splenomegaly and cytokine elevation in a CML mouse model

The persistence of leukemic stem cells (LSCs) represents a problem in the therapy of chronic myeloid leukemia (CML). Hence, it is of utmost importance to explore the underlying mechanisms to develop new therapeutic approaches to cure CML. Using the genetically engineered ScltTA/TRE-BCR::ABL1 mouse model for chronic phase CML, we previously demonstrated that the loss of the docking protein GAB2 counteracts the infiltration of mast cells (MCs) in the bone marrow (BM) of BCR::ABL1 positive mice. Here, we show for the first time that BCR::ABL1 drives the cytokine independent expansion of BM derived MCs and sensitizes them for FcεRI triggered degranulation. Importantly, we demonstrate that genetic mast cell deficiency conferred by the Cpa3^Cre allele prevents BCR::ABL1 induced splenomegaly and impairs the production of pro-inflammatory cytokines. Furthermore, we show in CML patients that splenomegaly is associated with high BM MC counts and that upregulation of pro-inflammatory cytokines in patient serum samples correlates with tryptase levels. Finally, MC-associated transcripts were elevated in human CML BM samples. Thus, our study identifies MCs as essential contributors to disease progression and suggests considering them as an additional target in CML therapy. Mast cells play a key role in the pro-inflammatory tumor microenvironment of the bone marrow. Shown is a cartoon summarizing our results from the mouse model. BCR::ABL1 transformed MCs, as part of the malignant clone, are essential for the elevation of pro-inflammatory cytokines, known to be important in disease initiation and progression.

Sugar infusion into trees: A novel method to study tree carbon relations and its regulations

Many carbon-related physiological questions in plants such as carbon (C) limitation or starvation have not yet been resolved thoroughly due to the lack of suitable experimental methodology. As a first step towards resolving these problems, we conducted infusion experiments with bonsai trees (Ficus microcarpa) and young maple trees (Acer pseudoplatanus) in greenhouse, and with adult Scots pine trees (Pinus sylvestris) in the field, that were "fed" with ¹³C-labelled glucose either through the phloem or the xylem. We then traced the ¹³C-signal in plant organic matter and respiration to test whether trees can take up and metabolize exogenous sugars infused. Ten weeks after infusion started, xylem but not phloem infusion significantly increased the δ¹³C values in both aboveground and belowground tissues of the bonsai trees in the greenhouse, whereas xylem infusion significantly increased xylem δ¹³C values and phloem infusion significantly increased phloem δ¹³C values of the adult pines in the field experiment, compared to the corresponding controls. The respiration measurement experiment with young maple trees showed significantly increased δ¹³C-values in shoot respired CO₂ at the time of four weeks after xylem infusion started. Our results clearly indicate that trees do translocate and metabolize exogenous sugars infused, and because the phloem layer is too thin, and thus xylem infusion can be better operated than phloem infusion. This tree infusion method developed here opens up new avenues and has great potential to be used for research on the whole plant C balance and its regulation in response to environmental factors and extreme stress conditions.

The secreted inhibitor of invasive cell growth CREG1 is negatively regulated by cathepsin proteases

Previous clinical and experimental evidence strongly supports a breast cancer-promoting function of the lysosomal protease cathepsin B. However, the cathepsin B-dependent molecular pathways are not completely understood. Here, we studied the cathepsin-mediated secretome changes in the context of the MMTV-PyMT breast cancer mouse model. Employing the cell-conditioned media from tumor-macrophage co-cultures, as well as tumor interstitial fluid obtained by a novel strategy from PyMT mice with differential cathepsin B expression, we identified an important proteolytic and lysosomal signature, highlighting the importance of this organelle and these enzymes in the tumor micro-environment. The Cellular Repressor of E1A Stimulated Genes 1 (CREG1), a secreted endolysosomal glycoprotein, displayed reduced abundance upon over-expression of cathepsin B as well as increased abundance upon cathepsin B deletion or inhibition. Moreover, it was cleaved by cathepsin B in vitro. CREG1 reportedly could act as tumor suppressor. We show that treatment of PyMT tumor cells with recombinant CREG1 reduced proliferation, migration, and invasion; whereas, the opposite was observed with reduced CREG1 expression. This was further validated in vivo by orthotopic transplantation. Our study highlights CREG1 as a key player in tumor–stroma interaction and suggests that cathepsin B sustains malignant cell behavior by reducing the levels of the growth suppressor CREG1 in the tumor microenvironment.

[Immunosuppression, Surgery, Complication?]

Immunosuppression, Surgery, Complication? Abstract. Surgical conditions sometimes pose major diagnostic and therapeutic challenges for immunosuppressed patients. Especially in patients suffering from diseases with potential septic emergencies or postoperative complications, the indication for elective surgery should be discussed at an early stage. This is best done across disciplines, involving all experts and the patient.

Determinants of forearm strength in postmenopausal women

Bone strength at the ultradistal radius, quantified by micro-finite element modeling, can be predicted by variables obtained from high-resolution peripheral quantitative computed tomography scans. The specific formula for this bone strength surrogate (-555.2 + 8.1 × [trabecular vBMD] + 19.6 × [cortical area] + 4.2 × [total cross-sectional area]) should be validated and tested in fracture risk assessment.

INTRODUCTION

The purpose of this study was to identify key determinants of ultradistal radius (UDR) strength and evaluate their relationships with age, sex steroid levels, and measures of habitual skeletal loading.

METHODS

UDR failure load (~strength) was assessed by micro-finite element (μFE) modeling in 105 postmenopausal controls from an earlier forearm fracture case-control study. Predictors of bone strength obtained by high-resolution peripheral quantitative computed tomography (HRpQCT) in this group were then evaluated in a population-based cohort of 214 postmenopausal women. Sex steroids were measured by mass spectrometry.

RESULTS

A surrogate variable (-555.2 + 8.1 × [trabecular vBMD] + 19.6 × [cortical area] + 4.2 × [total cross-sectional area]) predicted UDR strength modeled by μFE (R(2) = 0.81), and all parameters except total cross-sectional area declined with age. Evaluated cross-sectionally, the 21% fall in predicted bone strength between ages 40-49 years and 80+ years more resembled the change in trabecular volumetric bone mineral density (vBMD) (-15%) than that in cortical area (-41%). In multivariable analyses, measures of body composition and physical activity were stronger predictors of UDR trabecular vBMD, cortical area, total cross-sectional area, and predicted bone strength than were sex steroid levels, but bio-available estradiol and testosterone were correlated with body mass.

CONCLUSIONS

Bone strength at the UDR, as quantified by μFE, can be predicted from variables obtained by HRpQCT. Predicted bone strength declines with age with changes in UDR trabecular vBMD and cortical area, related in turn to reduced skeletal loading and sex steroid levels. The predicted bone strength formula should be validated and tested in fracture risk assessment.

Assessing forearm fracture risk in postmenopausal women

A diverse array of bone density, structure, and strength parameters were significantly associated with distal forearm fractures in postmenopausal women, but most of them were also correlated with femoral neck areal bone mineral density (aBMD), which provides an adequate measure of bone fragility at the wrist for routine clinical purposes.

INTRODUCTION

This study seeks to test the clinical utility of approaches for assessing forearm fracture risk.

METHODS

Among 100 postmenopausal women with a distal forearm fracture (cases) and 105 with no osteoporotic fracture (controls), we measured aBMD and assessed radius volumetric bone mineral density, geometry, and microstructure; ultradistal radius failure load was evaluated in microfinite element (microFE) models.

RESULTS

Fracture cases had inferior bone density, geometry, microstructure, and strength. The most significant determinant of fracture in five categories were bone density (femoral neck aBMD; odds ratio (OR) per standard deviation (SD), 2.0; 95% confidence interval (CI), 1.4-2.8), geometry (cortical thickness; OR, 1.5; 95% CI, 1.1-2.1), microstructure (structure model index (SMI); OR, 0.5; 95% CI, 0.4-0.7), and strength (microFE failure load; OR, 1.8; 95% CI, 1.3-2.5); the factor-of-risk (applied load in a forward fall / microFE failure load) was 15% worse in cases (OR, 1.9; 95% CI, 1.4-2.6). Areas under receiver operating characteristic curves (AUC) ranged from 0.62 to 0.68. The predictors of forearm fracture risk that entered a multivariable model were femoral neck aBMD and SMI (combined AUC, 0.71).

CONCLUSIONS

Detailed bone structure and strength measurements provide insight into forearm fracture pathogenesis, but femoral neck aBMD performs adequately for routine clinical risk assessment.

Cosmetic issues of abdominal surgery: results of an enquiry into possible grounds for a natural orifice transluminal endoscopic surgery (NOTES) approach

BACKGROUND AND STUDY AIMS

Decreased scarring is an advantage of minimally invasive surgery. The new experimental technique of natural orifice transluminal surgery (NOTES) aims at totally scarless surgery. We examined the general attitudes of patients and unaffected persons towards scarless surgery.

METHODS AND PARTICIPANTS

We used a 7-item questionnaire in structured interviews with hospital visitors, following detailed standardized explanation of terms used and of possible complications, to groups of 10 participants, during an "open ward" day. A visual analog scale (VAS) from 1 (none) to 10 (very much) was used for all but one item. Questions concerned the importance of cosmetic results in abdominal surgery, satisfaction regarding existing scars, hypothetical acceptance of increased risk as a trade-off for the absence of scars, and other issues. Data were analyzed for participants overall, and for three age groups and both sexes.

RESULTS

292 participants (male : female 1 : 1; mean age 43 years) completed the questionnaire. Cosmetic issues were rated as important (median 8), but acceptance of existing scars was also high in those affected (median 8, n=68). Approval of scarless surgery decreased with a presumed risk increase (from score 9 down to score 5), and overall an increase in risk of 10 % was judged to be acceptable as a trade-off for total absence of scarring. Younger people tended to be less satisfied with scars, but were also less inclined than older people to accept higher surgical risk in this hypothetical context.

CONCLUSIONS

People generally seem to favor scarless abdominal surgery, even with some increase in risk.

Deaths caused by malaria in Switzerland 1988-2002

Despite sophisticated intensive medicine, between one and three malaria-associated deaths occur annually in Switzerland. In this retrospective study, 33 deaths (25 men and 8 women) caused by falciparum malaria reported in Switzerland from 1988 to 2002 were analyzed. The case fatality ratio (CFR) for the falciparum infections for the 15-year period was 1.2%, with a peak of 2.2% in 1991. Sub-Saharan Africa was the source of all the imported fatal infections. Non-immune Europeans had a significantly higher case fatality ratio than the non-Europeans (1.7% versus 0.2%; P < 0.001). Careless use or non-use of prophylaxis, sometimes because of physicians giving unsatisfactory pre-travel advice, and initially missed diagnosis post-travel were factors that contributed to the development of severe infections leading to death. Travelers should be sensitized to the risk of malaria by well-informed general practitioners. Updated information is readily available (www.safetravel.ch). Regarding diagnosis and treatment, greater physician awareness of the disease is needed, and expert advice should be sought without hesitation. Rapid malaria tests may be a useful diagnostic adjunct in centers where microscopic expertise is lacking. Falciparum malaria in a non-immune patient is an emergency requiring immediate treatment.

Multidimensional analysis of learning curves in laparoscopic sigmoid resection: eight-year results

PURPOSE

The number of operations to reach a plateau phase in colorectal laparoscopic surgery is still under debate. There are few publications reporting on multidimensional assessment of the learning curve, including operation time and complication and conversion rates. The purpose of this study was to define a multidimensional learning curve for sigmoid resection performed by two surgeons with experience in laparoscopic surgery.

METHODS

Between 1993 and 2001 from a total of 715 laparoscopic colorectal procedures, two surgeons performed self-educated 338 sigmoid resections. Demographic data, indications for surgery, procedure performed, operation time, frequency and kind of complications, conversion rate, and days to discharge were recorded. The moving average method was used to demonstrate the change of the operation time. The cumulative sum technique was used to chart the changes in the conversion and complication rates.

RESULTS

Surgeon A performed 199 and Surgeon B 139 sigmoid resections. The operation time decreased from 225 minutes to 169 minutes after approximately 90 operations for Surgeon A and from 270 minutes to 223 minutes after 110 operations for Surgeon B. Based on a decline in intraoperative complications and conversion rate, the steady state was reached after approximately 70 to 80 interventions for both surgeons.

CONCLUSIONS

The assessment of a learning curve should not be limited to measurement of a decrease in operation time but should also include the conversion and complication rates. The cumulative sum technique and moving average method as proposed in this study seem appropriate to evaluate the learning curve in this clinical domain. Our findings might be especially useful for those planning training programs in laparoscopic surgery.

Gas-phase structures of acetyl peroxynitrate and trifluoroacetyl peroxynitrate

The molecular structures and conformational properties of acetyl peroxynitrate (PAN, CH3C(O)OONO2) and trifluoroacetyl peroxynitrate (FPAN, CF3C(O)OONO2) were investigated in the gas phase by electron diffraction (GED), microwave spectroscopy (MW), and quantum chemical methods (HF/3-21G, HF/6-31G*, MP2/6-31G*, B3PW91/6-31G*, and B3PW91/6-311+G*). All experimental and theoretical methods show the syn conformer (C=O bond of acetyl group syn to O-O bond) to be strongly predominant relative to the anti conformer. The O-NO2 bonds are extremely long, 1.492(7) A in PAN and 1.526(10) A in FPAN, which correlates with their low bond energy and the easy formation of CX3C(O)OO* and *NO2 radicals in the atmosphere. The O-O bonds (1.418(12) A in PAN and 1.408(8) A in FPAN) are shorter than that in hydrogen peroxide (1.464 A). In both compounds the C-O-O-N dihedral angle is close to 85 degrees.

The Rotational-Torsional Spectrum of the g'Gg Conformer of Ethylene Glycol: Elucidation of an Unusual Tunneling Path

The microwave spectrum of the energetically unfavored g'Gg conformer of ethylene glycol (CH(2)OH&bond;CH(2)OH) is reported. This spectrum is dominated by an interconversion geared-type large-amplitude motion during which each OH group in turn forms the intramolecular hydrogen bond. The microwave spectrum has been analyzed with the help of a Watson-type Hamiltonian plus a 1.4-GHz tunneling splitting. The rotational dependence of this tunneling splitting has been examined using an IAM approach and this yielded qualitative information on the tunneling path the molecule uses to interconvert between its two most stable conformers. Unexpectedly, but in agreement with ab initio calculations, when tunneling occurs between the energetically equivalent g'Gg and gGg' conformers, the OH groups are rotated stepwise through 240 degrees in the sense of a flip-flop rather than a concerted rotation and the molecule goes through the more stable g'Ga and aGg' forms. The electronic reasons for preferring a long rather than a short rotational path via a gGg form are discussed using calculated adiabatic vibrational modes. Copyright 2001 Academic Press.

[Early postoperative nutrition after laparoscopic and open colorectal resection]

BACKGROUND

Discussions concerning postoperative nutrition were brought up again with laparoscopic colorectal surgery. We are looking whether there is any difference between open and minimal invasive procedures with respect to the start of oral intake.

METHODS

In a prospective controlled trial 152 patients were analysed after laparoscopic (n = 85) or open (n = 67) colorectal resections. At the first postoperative day fluid intake was unlimited and from the second day regular food was permitted according to the patients desire.

RESULTS

No influence on the beginning of nutrition was by age, diagnoses, type of operation nor their duration. Wound infection and specially cardiopulmonal decompensation prolonged lack of appetite, however, not a pneumonia. There was no increase of anastomotic leak rate. At day 4, a highly significant difference was found between laparoscopic and open surgery with 90% and 60% of patients having started regular nutrition (p < 0.001).

CONCLUSION

Early postoperative oral nutrition does not increase complication rate. Patients after laparoscopic procedures start earlier eating compared with those after conventional surgery. We recommend early postoperative oral intake after both techniques according to the patients desire.

[Intraperitoneal tumor seeding in colorectal carcinoma surgery--follow-up of a comparison of laparoscopic versus open procedure]

Follow-up 71 patients during 20 months (12-29) operated on for colorectal cancer by laparoscopic or open surgery demonstrated no correlation between port-side metastases (1/35) or tumor recurrences (5/71) and intraperitoneal tumor cells. All these patients were cytologic-negative; however, all were initial in an advanced tumor stage (pT3-4, N1-3). We conclude from these results that free tumor cells during operation do not seem to influence outcome or the development of port-side metastases.

Vibrational Information Extracted from Inertial Defects: The Complete General Valence Force Field for 1,1-Difluoroethene

The method of extracting harmonic information from inertial defect differences has been used to obtain sufficient information for a determination of the complete force field for 1,1-difluoroethylene. The presumption that inertial defect differences for non-totally-symmetric vibrations of orthorhombic molecules contain purely harmonic information (1992. D. Christen, J. Mol. Spectrosc. 151, 1-11) must be revoked, however. Copyright 1998 Academic Press. Copyright 1998Academic Press

[Rectal prolapse]

Rectal prolapse is the transposition of the entire rectal wall into the rectal lumen, the anal canal or through the anal canal out side. It differs from anal prolapse in thickness, circular plication of the mucosa and, if large, its extent. The cause is not clearly established, but disorders in bowel movement seem to be of importance. Symptoms reach from the feeling of incomplete evacuation to defecation block and irreducible prolapse. The diagnosis of outer prolapse is easy. The inner prolapse [intussusception] can be suspected by anamnesis and in the presence of solitary rectal ulcer. Defecography gives the conclusive examination. Conservative therapy is analogous to hemorrhoids: Fibres and sufficient liquid intake. Operative procedures can be divided in transabdominal and perineal procedures. From the latter Delorme's procedure gives good results with low stress for the patient. Of the transabdominal procedures we favor rectopexy with Ivalon-sponge, preservation of the lateral bands and sigmoid resection. This procedure can easily be done by laparoscopy. Postoperative constipation is observed above all if the lateral bands are dissected and no sigmoid resection is done. Preexistent constipation Improves in about 50% of the cases. Same does incontinence.

[Technique and results of laparoscopic rectum resection]

The general principles of oncologic operations for colorectal cancer are the same for both open and laparoscopic surgery. Isolation of the tumor by occlusion of the intestinal lumen, early blockage of venous outflow, complete resection of the lymph node bearing mesenterium, high ligation of the artery and prevention of tumor cell dissemination during extirpation of the specimen are the most important factors. We present our technique for laparoscopic abdominoperineal resection, which fulfills the above mentioned criteria. From June 1993 to October 1994 we operated on 19 patients (median age 68 [47-91] years; male/female ratio 10/9). Laparoscopic abdominoperineal resection of the rectum was palliative in 3 patients and curative in 16. Tumors were located 3 (1-8) cm from the anal verge. In 3 patients the operation was converted to open surgery. Intraoperative complications were encountered in 3 patients. Median operation time was 300 (200-400) minutes and postoperative morbidity 8/19 (42%) leading to reoperation in one patient. 30-day mortality was nil. Three patients died 5, 8, and 14 months postoperatively due to metastatic disease (all 3 after initial palliation). One patient had local recurrence and liver metastasis and died 14 months after operation. Another patient died from liver metastases. In one patient a single liver metastasis was successfully removed. 14 patients were tumor-free after a median follow-up of 10 (3-14) months. There was no implantation metastasis on a trocar site. Laparoscopic abdominoperineal resection of the rectum is feasible and the results are comparable with those of open surgery. Local recurrence rate and incidence of liver metastases are comparable with open surgery after this short follow-up. However, 5-year survival is needed to judge the oncological radicality of laparoscopic abdominoperineal resection of the rectum.

[Intraperitoneal tumor seeding in colorectal carcinoma surgery--a comparison of laparoscopic versus open procedures in a longitudinal study]]

Tumor cell spread during laparoscopically assisted (n = 35) and open (n = 27) resections of colorectal cancer or patients with peritoneal carcinomatosis (PC) (n = 5) was studied by repeated lavage. Positive cytology was found in 3% during laparoscopy, 11% during open surgery and 80% in PC. We conclude that the risk of cancer cell mobilisation is minimal in laparoscopic surgery.

[Does laparoscopic colonic carcinoma surgery satisfy the radicality criteria of open surgery?]

Minimal invasive surgery is applicable to almost all colorectal operations, with major benefit for the patient. Technically even cancer operations can be performed. However, in laparoscopic assisted colorectal surgery the question of radicality outweighs that of performability and patient comfort. From a prospective series of 88 laparoscopic colorectal operations, 36 were for carcinoma. 34 patients who underwent conventional surgery were matched with regard to age, sex, type of operation and tumor stage (TNM, grading) to compare the two techniques. The two interventions followed exactly the same guidelines. We compared the length of the fixed specimens, the number of resected lymph nodes and the need for blood transfusions. Postoperative complications were noted and follow-up was 3-12 months. The data obtained showed no difference between the two treatment groups, with a slight trend towards laparoscopic surgery with regard to number of resected lymph nodes. A portside metastasis was observed 9 months after an initial tumor stage T4N1M1. The close relation between the portside and infiltration of the adenocarcinoma into the abdominal wall together with a drain placed through this whole was suspected to be the cause of this complication. We conclude that laparoscopic assisted colorectal surgery for cancer is equal to open operation regarding radicality of resection. Long term results are mandatory to determine the value of minimal invasive surgery in the field of oncology.

[How safe is laparoscopic colon surgery?]

Like any new technique, laparoscopic colon surgery must display results of the same or even better quality than established methods. In this hospital every laparoscopic colon operation has been registered since 1993. Patients were informed orally or in writing that the laparoscopic procedure is a new surgical technique and that, in particular, long term results in colon carcinoma are lacking. Patients who did not undergo the laparoscopic method were those who did not agree to this type of surgery, had tumor infiltrations without extensive liver metastases, or tumor sizes where laparotomy to retrieve the specimen is not much smaller than the open surgery incision. All operations without exception were performed by two laparoscopically skilled abdominal surgeons. We used four 12 mm Troicarts placed in a diamond position, the criteria for mobilization and resection strictly following those of open surgery. In rectosigmoid resection the specimens were extracted suprapubically, with simultaneous implantation of the anvil, in the other cases at appropriate sites. The anastomoses were created either by the double stapling technique or with a single layer running suture. 88 patients underwent operation. The change to open surgery was 11%. The reasons for the change were chiefly inflamed, bleeding diverticulitis tumor, carcinoma infiltrations and, in one case, bleeding. The anastomosis failure rate of the descendorectostomy, and in all laparoscopic colon operations, was 4% and compares favourably with the literature. This was also true of stenosis incidence. The wound infection rate is on the whole the same as for open surgery. The complication in the descendorectostomy is reduced by half in the laparoscopic procedure.(ABSTRACT TRUNCATED AT 250 WORDS)

Studies in the Cycloproparene Series: Reactions With Radicals

The behaviour of 1H-cyclopropabenzene (1) and 1H-cyclopropa[b]naphthalene (23) towards a variety of radicals results in opening of the three- membered ring to give ortho -substituted benzyl and 2-methylnaphthalene derivatives, e.g. (13) and (28), respectively. Ring expansion into the cycloheptatriene manifold by way of addition to the bridge bond and norcaradiene formation have not been observed. Analogous reactions with the methylidenecyclopropa [b] naphthalenes (33) and (34) lead to much decomposition, and provide little evidence for the C1cycloproparenyl radicals (35) and (36).

[Anal condylomata acuminata in HIV positive patients]

Since July 1986 we started with following all patients with condylomata acuminata including HIV-testing and human papilloma virus (HPV) identification by DNA-DNA-hybridisation (southern blot). Seventy patients are included, 39 of them are seropositive. The ratio male to female is 59 to 11, in seropositives 35 to 4, in negatives 24 to 7. The average age is 28 and 31 years respectively. The number of homosexuals and junkies is significantly higher in seropositives. Seventeen patients are in HIV-stage II, 11 in stage III and 10 in stage IV according to CDC-classification. Characteristic for the seropositives was an extensive growth on the rectal mucosa and the very rapid growth of initially subtotally resected lesions in order to prevent stenosis. Sixty-five patients were treated by one stage radical operation with electrocauter. Surprisingly recurrency is more frequent in seronegatives, however, the lesion is much smaller in this group. A hypothesis to explain this observation is brought forward. Postoperative complications occurred only in HIV-stages III and IV. We therefore recommend single shot antibiotic prophylaxis in these patients. The HPV-identification showed no malignancy associated HPV-types in both groups but a higher incidence of HPV 11 in higher HIV-stages which we cannot explain. We conclude from our series that, if operation is indicated, one stage radical electrocoagulation of condylomata acuminata is a necessary procedure in seropositive patients and a save one in negative patients but antibiotic prophylaxis should be given in stage III and IV. Anal condylomata acuminata are a hint for possible HIV-positivity.

[Anal condylomata acuminata. A prospective comparison of HIV positive and negative patients]

Between July 1986 and May 1987 23 patients suffering from anal condylomata acuminata were treated at the University Hospital of Zurich. The influence of HIV-infection on the disease is described. An almost equal frequency of recurrencies between positives and negatives was observed in a three year follow-up time. However, in positive patients recurrence was earlier and much more extensive. A two-stage procedure which sometimes is advocated in very extensive lesions gave very bad results in HIV positives. We use a radical excision by electrocoagulation on the mucosa and perianally and avoid circular necrosis in the lower anal canal only. Infectious complications are not to be feared except in patients with symptomatic HIV-infection resulting in the recommendation for a antibiotic prophylaxis in such cases.

Anogenital warts of the condyloma acuminatum type in HIV-positive patients

Anogenital warts of the condyloma acuminatum type seem to occur quite often during HIV infection. These warts--according to our study--are not commonly caused by malignancy-associated human papilloma virus types, but by types 6 and 11 as seen in the nonimmune-compromised population. Widespread condylomata acuminata may appear in rather early stages of HIV infection and they may therefore represent early warning signs of HIV infection.